







COPYRIGHT DEPOSIT. 



SHEET-METAL WOEK 



A MANUAL OF PRACTICAL SELF-INSTRUCTION IN THE ART OF 

PATTERN DRAFTING AND CONSTRUCTION WORK 

IN LIGHT- AND HEAVY-GAUGE METAL, 

INCLUDING SKYLIGHTS, ROOFING, 

CORNICE WORK, ETC. 



WILLIAM NEUBECKER 

INSTRUCTOR, SHEET-METAL DEPARTMENT 
NEW YORK TRADE SCHOOL 



ILLUSTRATED 



AMERICAN TECHNICAL SOCIETY 

CHICAGO 

1920 



<-g>^ 



/ 









Coptbight, 1917, 1919, 1920, by 
AMERICAN TECHNICAL SOCIETY 



COPYRIGHTED IN GREAT BRITAIN 
ALL BIGHTS RESERVED 



y>-\°\tf& 



©CI.A59793? 

OCT 21 1320 



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INTRODUCTION 

THE importance of sheet-metal work in modern manufactur- 
ing developments is vastly greater than those not actually in 
touch with the work would imagine. Its use in building sky- 
lights, roofs, and cornices are visible and obvious applications 
of the industry, but there are countless operations in pressed 
metal manufacturing where the principles discussed herein find 
their most important application, and it is to help those who are 
actually working in this field that this volume has been printed. 
The sheet-metal draftsman has a very different problem in many 
respects from that of the mechanical draftsman. The mechanical 
draftsman has to deal, in the main, with square or circular 
shapes, and he has perfectly definite plans or elevations to fashion 
from the specifications given. His surfaces also are flat, spherical, 
or cylindrical and will be shaped by the various machines found 
in a well-equipped machine shop. 

<J The sheet-metal draftsman, on the other hand, must have a 
deeper understanding of geometrical principles, of the areas of sur- 
faces, and many other matters not considered by the mechanical 
draftsman. He must be able, in addition to the simple drawing of 
the object, to make accurate developments of complex surfaces 
and do this so accurately that the sheet-metal form, made from 
his drawing, can be put together without waste and without 
distortion of the shape intended. 

<J The author of this book has had years of practical experience 
in sheet-metal work of all classes as well as abundant oppor- 
tunity to apply his experience in teaching the subject. All the 
studies worked out are typical and the details are so clearly pre- 
sented as to make the volume valuable for the beginner as well 
as for the most experienced metal worker. 



Digitized by the Internet Archive 
in 2011 with funding from 
The Library of Congress 



http://www.archive.org/details/sheetmetalworkmaOOneub 



CONTENTS 

PAGE 

Tools and methods of obtaining patterns 3 

Material of construction 3 

Shop tools 4 

Intersections and developments 5 

Parallel-line development 5 

Development by triangulation 15 

Approximate developments 22 

Workshop problems 26 

Sink drainer 26 

Conical boss. 28 

Hip bath 30 

Bathtub 32 

Funnel 36 

Strainer pail 36 

Emerson ventilator 42 

Elbows , 44 

Ship ventilator 57 

Weights of cast and wrought iron 62 

Copper 62 

Lead 62 

Brass 62 

Zinc 62 

Weights of sheet copper and zinc 63, 64 

Standard gauge for sheet iron and steel 65 

Weight of flat rolled iron 66-71 

Weights of square and round iron bars 72, 73 

Weights of angle and tee iron 74 

Problems for tight-gauge metal 75 

Oblique piping 75 

Rain-water cut-off 77 

Transition piece in rectangular pipe 80 

Curved rectangular chute 82 

Hopper register box 85 

Transition piece in circular pipe 86 

Pipe offset connection 88 

Three-way branch 90 

Two-branch fork 94 

Tapering flange 97 

Cylinder intersecting furnace top 100 

Coppersmith's problems 105 

Sphere 105 

Circular tank. ... ....;..,...... ,,...........,. 107 

Curved elbows 113 



CONTENTS r; .,- 

PAGE 

Workshop problems (continued) 

Brewing kettle 1 15 

Problems for heavy metal 116 

Boiler shells and stacks 117 

Moulded cap for stack 117 

Three-pieced elbow 122 

Pipe intersections , 124 

Gusset sheet on locomotive 126 

Scroll sign 128 

Skylights 133 

Skylight bars 133 

Reinforcing strips 133 

Core-plate 134 

Cap : 134 

Weight of glass 135 

Tools 136 

Shapes of bars and curbs 136, 137 

Raising sash 139 

Condensation gutters 140 

Single-pitch and double-pitch skylights 141, 142 

Ventilation 141 

Hip monitor skylight 142 

Photographer's skylight 142 

Flat extension skylight 142 

Hipped skylight without monitor 143 

Skylight of long span 143 

Gearings 144 

Development of patterns for hipped skylight 144 

Rules for obtaining length of ventilator 156 

Ridge 156 

Hip 157 

Jack 157 

Roofing 158 

Metal roofs 158 

Tin 158 

Copper 158 

Galvanized iron 158 

Building paper 158 

Tables of quantities 160 

Weights 161 

Gauges 161 

Metal 162 

Slates 162 

Shingles 162 

Hip coverings 162 

Roofer's tool 16S 

Roof mensuration. , , , ',. . 168 



CONTENTS 

PAGE 

Roofing (continued) 

Flat-seam roofing 167 

Gutters 168 

Flashings 169 

Sheet lead 170 

Soldering 172 

Covering a conical tower 174 

Standing-seam roofing 177 

Corrugated iron roofing and siding 182 

Measurements 184 

Deflection under loads 184 

Distances of supports 184 

Laying corrugated roofing and siding 185-190 

Cornice work 193 

Members of a corniee or entablature 193 

Cornice 194 

Dentil and modillion courses 194 

Bed and crown mould 194 

Modillion band and mould 194 

Dentil band and mould 194 

Panel mould 195 

Stop blocks 195 

Raking mouldings 196 

Miter. 196 

Drawings and tracings 197 

Methods of obtaining patterns 200 

Shapes of mouldings 202 

Problems in miter cutting 204 

Six-pointed star 236 

Eyebrow dormer 243 

Development of blanks for curved mouldings 249 

Shop tools 250 

Approximate blanks .* 250 

Hand and machine hammering 258 

IndeK 263 




w 



PAET I. 

The sheet-metal worker of today who wishes to succeed nrast 
snow far more than was necessary years ago. There are many 
good, practical sheet-metal workers in the trade who are handi- 
capped because they are unable to lay out the patterns that arise 
in their daily work. Notwithstanding the introduction of labor- 
saving machinery, the demand for good workmen has increased. 
While most sheet-metal workers acquire practical knowledge in the 
shop, they lack the technical education necessary to enable them to 
become proficient as pattern cutters and draftsmen. In this 
course, special attention is given to the fundamental principles 
that underlie the art and science of pattern drafting. 

Practical workshop problems will be presented, such as arise 
in everyday practice, thus giving the student the practical 
experience that usually comes only after long association with the 
trade. 

CONSTRUCTION. 

In constructing the various articles made from sheet metal, 
various gauges or thicknesses of metal are used. For all gauges 
from No. 20 to No. 30 inclusive, we assume in the development 
of the pattern, that we are dealing with no thickness, and we make 
no allowance for bending or rolling in the machine. But where 
the metal is of heavier gauge than No. 20, allowance must be made 
for shrinkage of the metal in the bending and rolling operations, 
which will be explained in connection with development in heavy 
sheet-metal work. Certain instructions for wiring, seaming, and 
transferring patterns are not given here as they more properly belong 
to tinsmithing work. It is sometimes the case that the capacity of a 
vessel or article must be determined, when the rules given in 
Mensuration should be followed. When figuring on sheet-metal 
work, the specifications sometimes call for various metals, such as 
galvanized sheet iron or steel, planished iron, heavy boiler plate, 



4 SHEET-METAL WORE 

band iron, square or round rods for bracing, etc., zinc, copper, or 
brass; and the weight of the metal must often be calculated together 
with that of stiffening rods, braces, etc. On this account it is 
necessary to have tables which can be consulted for the various 
weights. 

TABLES. 

There is a wide difference between gauges in use, which is 
very annoying to those who use sheet metal rolled by different 
firms according to the various gauges adopted. It would be well 
to do away with gauge numbers, and use the micrometer caliper 
shown in Fig. 1, which determines the thickness of the metal by the 
decimal or fractional parts of an inch. 




Pig.l. 



This is the most satisfactory method for the average mechanic 
who works sheet metal manufactured by firms using different 
gauges. The tables on pages 61 to 74 can be consulted when 
occasion arises. 

SHOP TOOLS. 

In allowing edges for seaming and wiring, we must bear in 
mind that when a seam is to be grooved by hand or machine the 
allowance to be made to the pattern should conform to the rolls in 
the machine or the hand tools in use. The edges of the pattern 
are usually bent on the sheet-iron folder, or brake, while the seam 
can be seamed or grooved with the hand groover or giant grooving 
machine. "Where round pipe work is done in lengths up to 8 feet, 
the slip roll former is used, while square or rectangular pipes are 
bent up on the brake in 8-foot lengths. Where pipes, elbows, 



SHEET-METAL WORK 5 

stove bodies, furnace shells, metal drums, etc., are made, the sheets 
are cut square on the large squaring shears, rolled, grooved, and 
stiffened, by beading both ends in the beading machine, using 
ogee rolls. There is also a special machine for seaming the cross 
seams in furnace pipes, also a set of machines for the manufacture 
of elbows used in sheet-metal work. As before mentioned, if these 
machines are at hand, it will be well to make slight modifications 
in the patterns so that both the machines and patterns may work 
to advantage. 

PATTERNS OBTAINED BY VARIOUS METHODS. 

In this course will be explained the four methods used in 
developing patterns for sheet-metal work, namely, parallel line, 
radial line, triangulation, and approximate developments. Further- 
more, practical problems illustrating these methods will be carefully 
worked out in every detail. 

INTERSECTIONS AND DEVELOPMENTS. 

The following problems on parallel line developments have 
been selected because they have a particular bearing on pipe work 
arising in the sheet-metal trade. All of the problems that will 
follow should be carefully studied, drawn on cheap paper, and 
proven by cardboard models. These models will at once show any 
error in the patterns which might otherwise be overlooked. As 
only the - Examination Plates are to be sent to the School, the 
student should draw all the other plates given in this course. 

The first problem to be drawn is shown in Fig. 2, being the 
intersection between a cylinder and octagonal prism. In drawing 
these problems for practice, make the cylinder and octagonal prism 
both 2 inches in diameter. The height of the cylinder from B to 
E should be 4| inches; and the length of the prism from G- to H, 
3 inches. Let A represent the plan of the cylinder, shown in 
elevation by B D E; and F, the section of the prism, shown in 
plan by Q- H IJ. Number the comers of the section F as shown, 
from 1 to 4 on both sides; and from these points draw horizontal 
lines intersecting the plan of the cylinder at 2'3' and 1'4' on both 
sides as shown. Establish a convenient intermediate point of 
intersection between the corners of the prism, as a and a in A, from 



6 



SHEET-METAL WORK 



which draw horizontal lines intersecting the section F at a ' , a ' , a ' , 
and a' . Take a tracing of the section F with its various inter- 
sections, and place it in its proper position as shown by F 1 , in the 




Fig. 2. 

center of the cylinder BODE, allowing the section to make a 
quarter turn, and bringing the points I' V at the top and bottom 
on a vertical line, while in the section F, b ' V are on a horizontal 



SHEET-METAL WOKK 7 

line. Prom the various intersections in F 1 , draw horizontal lines 
intersecting vertical lines drawn from similarly numbered inter- 
sections in the plan A, as shown in elevation. A line drawn 
through these points will represent the joint between the cylinder 
and prism. 

For the development for the prism, extend the line H I in plan 
as N K, upon which place the stretchout of all the points contained 
in the section F, as shown by similar figures and letters on N K. 
Through these points, at right angles to N K, draw lines which 
intersect with lines drawn from similarly numbered points and 
letters in plan, at right angles to J I. Trace a line through points 
thus obtained, and KLMN will be the desired pattern. To obtain 
the development for the opening in the cylinder, extend the line 
D E in elevation as S O, upon which place the stretchout of all the 
points contained in the half -circle A, as shown by similar numbers 
and letters on S O. At right angles to S O and through these 
points, draw lines intersecting horizontal lines drawn from inter, 
sections having similar numbers and letters in elevation, thus 
obtaining the intersections shown by T U V "W, which will be the 
shape of the opening to be cut into one-half of the cylinder. 

In Fig. 3 is shown the intersection between a hexagonal and 
quadrangular prism, the hexagonal prism being placed in elevation 
at an angle of 45° to the base line. When drawing this problem 
for practice, make the height of the quadrangular prism 4| inches, 
and each of its sides 2 inches. Place the hexagonal prism at an 
angle of 45° to the base line, placing it in the center of the 
quadrangular prism in elevation as shown; and inscribe the hex- 
agonal section in a circle whose diameter is 2^ inches. Let A 
represent the plan of the quadrangular prism placed diagonally as 
shown, above which draw the elevation BODE. In its proper 
position and proper angle, draw the outline of the hexagonal prism 
as shown by l v 1" 4" 4 V ; and on 1" 4" draw the half section as 
shown by F, numbering the corners 1" 2" 3 f and 4". From the 
corner 1' in the plan A, draw the center line V 4. Take a tracing 
of the half section F, and place it as shown by F 1 , placing the 
points V 4" in F on the center line in F 1 as shown. From the 
corners 1, 2, 3, and 4, draw lines parallel to the center line, intersect- 
ing the two sides of A (h V and 1' a) at 2' 3' and 1' 4', as shown. From 



SHEET-MBTAL WOKS 



these intersections draw vertical lines, which intersect by linea 
drawn parallel to 4" 4 V from corners having similar numbers in H s 
thus obtaining the points of intersection l v 2* 3 V and 4*. Dropping 
vertical lines from the intersections on the plane 1" 4 ff in elevation? 
and intersecting similarly numbered lines in plan, will give the 
horizontal section of 1* 4", as shown by 1° 2° 3 J and 4°. 




Por the development of the hexagonal prism, extend the line 
4* 1* as shown by H J, upon which place the stretchout of twice 
the number of spaces contained in the half section F, as shown by 
similar figures on the stretchout line H J. From these points, at 
right angles to H J, draw lines as shown, which intersect by lines 
drawn at right angles to the line of the prism from intersections 
1* to 4 V , thus obtaining ths. points of intersection l x to 4 X . Lines 



SHEET-METAL WORK I 9 

traced from point to point as shown by JKLH, will be the 
required development. The shape of the opening to be cut into the 
quadrangular prism, is obtained by extending the line D E in 
elevation as N O, upon which place the stretchout of one-half 
the section A, with the various points of intersection, as shown by 
similar figures on O N. At right angles to O N erect lines from 
these points, which intersect by lines drawn from similarly 
numbered intersections in elevation at right angles to the quad- 
rangular prism, thus obtaining the points of intersection 1'" to 4'" 
on both sides. Then NOPK will be the half development. 

Fig. 4 shows the intersection between two cylinders of equal 
diameters at right angles. Make the height of the vertical cylinder 
3 inches, that of the horizontal cylinder 1^ inches, and the diameters 
of both 2 inches. Let A represent the plan of the vertical cylinder, 
and B its elevation. Draw the plan of the horizontal cylinder C, 
shown in elevation by D placed in the center of the vertical 
cylinder. Draw the half section E in plan and divide it into 
equal parts, as shown from 1 to 3 to 1. In a similar manner draw 
the half section E 1 in elevation, which also divide into the same 
number of spaces as E, reversing the numbers as shown. 

The following suggestions are given to avoid confusion in 
numbering the points or corners of irregular or round sections in 
plan and elevation. If the half section E were bent on the line 1-1 
and turned upward toward the reader, and we should view this 
section from the front, the point 3 would be at the top, or, if bent 
downward, would be at the bottom; therefore the points 3 and 3 in 
elevation are placed at top and bottom. Now if the section E 1 in 
elevation were bent on the line 3-3 either toward or away from the 
reader, the point 1 when looking down would show on both sides as 
shown in plan, which proves both operations. No matter whether 
the form is simple, as here shown, or complicated as that which 
will follow, the student should use his imaginative power. Study 
the problem well; close your eyes and imagine you see the finished 
article before you, or, failing in this, make a rough model in the 
shop or a cardboard model at home, which will be of service. Now 
from the intersections in E, draw horizontal lines intersecting the 
circle A at 1', 2' and 3' on both sides. From these points erect 
perpendicular lines and intersect them with horizontal lines drawn 



10 



SHEET-METAL WORK 




Fig. 4. 



SHEET-METAL WORK 11 

from similarly numbered intersections in E 1 . Lines traced through 
these points 3" 2" V and 1" 2" 3' will be straight because both 
branches are of equal diameters. 

For the development of the cylinder D in elevation, extend 
the line 3-3 as shown by F G, upon which place the stretchout of 
twice the number of spaces contained in E 1 , as shown by similar 
numbers 3° to 1° to 3° to 1° to 3° on the stretchout line F G. 
From these points, at right angles to G F, draw lines, and 
intersect them by lines drawn parallel to the cylinder B from similar 
numbers in the joint line. Trace a line through these points in 
the development, when F G H I will be the desired shape. 

For the opening to be cut into the cylinder B to receive the 
cylinder D, extend the base of the cylinder B as shown by l v l v , 
upon which place the stretchout of the half circle A in plan, as 
shown by similar figures on the stretchout line l v l v . From these 
points erect perpendiculars, which intersect by lines drawn from 
similarly numbered intersections in elevation at right angles to the 
line of the cylinder B. Trace a line through the intersections 
thus obtained; J K L M will be the shape of the opening. 

Fig. 5 shows the intersection of two cylinders of unequal 
diameters at an angle of 45°. Make the diameters of the large and 
small cylinders 2 inches and \\ inches respectively; the height of 
the large cylinder 3 inches ; and the length of the small cylinder 
measured from its shortest side in elevation, 1 inch, placed at an 
angle of 45° in the center of the cylinder B. A represents the 
plan of the large cylinder struck from the center a and shown in 
elevation by B. Draw the outline of the small cylinder C at its 
proper angle, and place the half section D in its position as 
shown; divide it into. a number of equal spaces, as shown from 
points 1 to 5. Through the center a in plan, draw the horizontal 
line a 5 ; and with h as a center describe a duplicate of the half 
section D with the various points of intersection, as shown by D 1 , 
placing the points 1 and 5 on the horizontal line a 5. From the 
intersections in D 1 draw horizontal lines intersecting the large 
circle A at 3 ' to 3 ' as shown, from which points erect perpendicular 
lines; intersect them by lines drawn parallel to the lines of the 
smaller pipe from similarly numbered intersections in D. A line 



12 



SHEET-METAL WORK 



traced through the points thus obtained will represent the inter- 
section or miter joint between the two pipes. 

These same principles are applicable no matter what diameters 
the pipes have, or at what angle they are joined, or whether tb» 





» PLAN ^* 



pipe is placed as shown in plan or at one side of the center line. 

For the development of the small cylinder extend the line 5-1 

in elevation as shown by F E, upon which place the stretchout 



SHEET-METAL WOBK 



IS 



of the circle D 1 in plan, or twice the amount of D in elevation, 
as shown by similar figures on the stretchout line F E. At right 
angles to F E and through these small figures, draw lines which 
intersect with lines drawn at right angles to the lines of the 
small cylinder from similarly numbered intersections in the 
miter line in elevation. Trace a line through the points thus 
obtained; E F G will be the development for the cylinder C. 

To obtain the opening in the large 
cylinder extend the lines of the large 
cylinder in elevation as shown at the base 
by H J, upon which place the stretchout 
of the intersections contained in the circle 
A, being careful to transfer each space 
separately (as they are unequal) to the 
stretchout line H J. Through these points 
and at right angles to H J erect lines which 
intersect with horizontal lines drawn from 
similar points in the miter line in elevation 
A line traced through the points thus 
obtained, as shown by K L M N, will be 
the desired development. 

Fig. 6 shows the intersection between 
a quadrangular prism and sphere, the center 
of the prism to come directly over the center 
of the sphere. Make the diameter of 
the sphere 2^ inches, the sides of the 
prism 1^ inches, and the height from f 
to c' 2f inches. Draw the elevation of the 
sphere A which is struck from the center 
«, from which erect the perpendicular a b. With any point, as c, 
as a center and using the same radius as that used for A, describe the 
plan B. Through c draw the two diagonals at an angle of 45°, and 
draw the plan of the prism according to the measurements given. 
Now draw the elevation of the prism/ <?' and/' c, the sides of the 
prism intersecting the sphere at c and c ' . From either of these points 
draw a horizontal line intersecting the center line a b at d. Then 
using a as a center and a d as the radius, describe the arc e e ' 
intersecting the sides of the prism extended at e and e' \f e e' f 




Fig. 6. 



14 



SHEET-METAL WORK 



will be the development for one of the sides of the prism. In 
practice the four sides are joined in one. 

Fig. 7 shows the intersection of a quadrangular prism and 
sphere when the center of the prism is placed to one side of the 
center of the sphere. Make the diameter of the sphere the same 
as in the preceding figure; through x in the plan draw the 45° 
diagonal, and make the distance from x to A ^ inch, the sides of 
the prism 1 inch, and the height from E to c in elevation 1^ inches. 
Having drawn the elevation and plan of 
the sphere, construct the plan of the prism 
as shown by A B C D. Parallel to the 
center line x y project the prism in eleva- 
tion intersecting the sphere at a and c. 
Now since the center of the sphere is on 
one of the diagonals of the prism in plan, 
either two of the sides meeting at one end 
of that diagonal, as B C and C D, will be 
alike, and both will be different from the 
other two sides A B and A D, meeting at 
the opposite end of the diagonal. There- 
fore the line F a in elevation will be used 
in obtaining the development of D C in 
plan, while the line E c will be used in 
obtaining the development for the two 
sides D A and A B in plan. 

Now from a draw a horizontal line 
intersecting the center line x y at 5/ 
and using y as a center and y b as the 
radius, describe the arc G H intersecting 
Fig. 7. the sides of the prism extended to (Gl- 

and H. Then E F G H is the development for each side of the 
prism shown in plan by D C and C B. In a similar manner, from 
the intersection o in elevation draw a horizontal line intersecting 
the center line x y at d. Then using y as center and yd&s radius, 
describe an arc intersecting the sides of the prism at e and/! E 
TPfe will show the development for either side of the prism shown 
in plan by D A and A B. By connecting the points G and f it 
will be found that the line is a true horizontal line, which proves 




ELBOW PATTERNS* 



In all elbow work the difficulty lies in obtaining the correct rise of the 
miter line. By the use of a protractor this is overcome and thus the necessity 
of drawing a complete quadrant is avoided. Following the rule given in the 
illustration the rise can be easily found, when the throat and diameter of the 
pipe is known. 

In the upper table are shown various pieced elbows, having different 
degrees when finished, and the various miter lines. There are six miter pat- 
terns shown, the first for a 6-pieced elbow having 90° when completed; the 
second for a 4-pieced 90° elbow; the third for a 3-pieced 90° elbow; the fourth 
for a 2-pieced 70° elbow; the fifth for a 2-pieced 90° elbow, and the sixth for 
a 2-pieced 105 c elbow. 

No matter what size of throat the elbow may have, or what diameter 
or number of pieces, always follow the rule given in the illustration and obtain 
the miter line ; then place the half profile in its proper position and place the 
full girth of the pipe on the line shown in the pattern by similar numbers. 
By reversing the cut opposite the line 1-7-1 the pattern for the middle pieces 
is obtained, after which one cut can be placed into the other as shown on 
Page 48. 



* The illustration referred to will be found on the back of this page. 



SHEET-METAL WORK 15 

the two developments. Should the plan of the prism be so placed 
on the sphere that all sides would be different, then two elevations 
would be necessary so that the intersections of all the sides could 
be shown. 

Developments by Triangulation. In developing sheet-metal 
work of irregular forms, patterns are required whioh cannot be 
developed by either the parallel or radial-line methods. These 
irregular shapes are so formed that although straight lines can be 
drawn upon them the lines would not run parallel to one another, 
nor would they all incline to a common center. In the methods 
previously described, the lines in parallel developments run parallel 
to one another, while in radial-line developments all the lines meet 
at a common center. Hence in the development of any irregular 
article, it becomes necessary to drop all previous methods, and 
simply proceed to measure up the surface of the irregular form, 
part by part, and then add one to another until the entire surface 
is developed. To accomplish this, we have merely to make use of 
one of the simplest of all geometrical problems, namely, to construct 
a triangle having given the three sides. This problem is solved 
very early in Mechanical Drawing. To carry out this method 
it is necessary only to divide the surface of the plan or elevation 
of any irregular article into a number of equal parts. Use the 
distances in plan as the bases of the triangles, and the distances in 
elevation as the altitudes or heights of the triangles, or vice versa; 
and then find the hypothenuse by connecting the two given lengths. 

To illustrate this simple principle Fig. 8 has been prepared. 
Let A B C D represent the plan of a plane surface, shown in 
elevation by A 1 B 1 . We know that the true length of the plane 
is equal to A 1 B 1 and the true width is equal to A D or B in plan. 
We also know that the vertical height from the bottom of the plane 
A 1 to the top B 1 is equal to B 1 b as shown. But suppose we want 
to obtain the true length of the diagonal line B D in plan on the 
developed plane. To obtain this it will be necessary only to take 
the length of B D, place it from b to D 1 , and draw a line as shown 
from B 1 to D 1 , which is the length desired. 

While this may look very simple, it is all that there is to 
triangulation, and if the student thoroughly understands the simple 
principle and studies the problems whioh will follow, he will have 



16 



SHEET-METAL WORK 



no trouble in applying this principle in complicated work. To 
make it still clearer we will prove the length of the line B 1 D 1 . 
Take the distance of A 1 B 1 , place it in plan as shown by A B 2 , and 
complete the rectangle A B 2 C 2 D. Draw the diagonal B 2 D, being 
the length sought, which will be found to equal B 1 D 1 in elevation. 
When drawing this problem in practice, make the plan 4 by 6 inches 
and the vertical height in elevation 5 inches. 

In obtaining developments by triangulation, the student should 
use all of his conceptive powers as previously explained. Before 

making any drawing, he must 
see the article before him in his 
mind's eye, so to speak, before 
he can put it down on paper. 
Therefore we want to impress 
upon the student the necessity of 
drawing all the problems that will 
follow in this part and in the Prac- 
tical Workshop Problems. It 
should be understood that tri- 
angulation is not given as an 
PLAN _w alternative method, but is used 

Fig. 8. when no other method can be 

employed, and without it no true pattern could be obtained for 
these irregular shapes ; hence the necessity of close study,, 

In Fig. 9 is shown an irregular solic' whose base and top are 
triangles crossing each other, and in which the principle just 
explained will be put to practical test Inscribe the triangles 
shown in plan in a circle whose radius is equal to a 1, or 1^ inches, 
and make the height of the article in elevation 2 inches. The 
dotted triangles 1 2 3 in plan represent the section of the article on 
the line 2-3 in elevation; and the solid triangle I 1 2 1 3 1 in plan, the 
section on the line 2 1 3 1 in elevation. Now connect the two sections 
in plan by drawing lines from 1 to 2 1 and to 3 1 , from 2 to 2* and to 
I 1 , and from 3 to l 1 and to 3 1 . In a similar manner connect the 
points in elevation as shown. It now becomes necessary to obtain 
a triangle giving the true length of the lines connecting the 
corners of the triangle in plan, and as all of these lines are equal 
ooly one triangle is necessary. Therefore take the distance from 




SHEET-METAL WORK 



17 



\ 

\ 

V 


/ 1 \ 
f 1 \ 


1 1\ 

/ 
/ 
/ 






\i 




1S^H%&\ 



1 to 2 1 in plan and place it on the line 3-2 extended in elevation, 
as shown from 2 to 1°, and draw a line from 1° to 2 1 , which is the 
desired length. 

For the pattern, proceed as is shown in Fig. 10. Take the 
distance of any one of the sides in the triangle, as 1-2 in Fig. 9, 
and place it on the horizontal line 3' elevation a* 
1-2 in Fig. 10. Then using 1 and 

2 as centers, with 1° 2 1 in elevation 
in Fig. 9 as radius, describe the 
arcs in Fig. 10 intersecting each 
other in 2 1 . Then 1 2 2 1 will be 
the pattern for one of the sides 
shown in plan in Fig. 9 by 1 2 2 1 . 
Proceed in this manner in Fig. 10 
as shown by the small arcs; or a 
tracing may be taken of the one 
side 1 2 2 1 , and traced as shown 
until six sides are obtained, which 
will be the full pattern and which 
is numbered to correspond to the 
numbers in plan. 

In Figs. 11, 12, and 13 are shown the methods used in develop- 
ing a scalene cone. The method of obtaining the development of 
any scalene cone, even though its base is a perfect circle, is governed 
by the same principle as employed in the last problem on triangu- 



Fig. 9. 




Fig. 10. 

lation It is well to remember that any section of a scalene cone 
drawn parallel to its base will have the same shape (differing of 
course in size) as the base. This is equally true of articles whose 



IS 



SHEET-METAL WORK 



bases are in the shape of a square, rectangle, hexagon, octagon, or 
any other polygon. What has just been explained will be proven 
in connection with Fig. 11, in which ABO represents a side 
elevation of a scalene cone, whose plan is shown by 1 4 1 7 4 C 1 . 
Draw any horizontal line, as A D, on which set off the distances 




A B equal to 3 inches and B D equal to 2£ inches, and the 
vertical height D C equal to 4^ inches. Draw lines from B and 
A to 0, which completes the elevation. In its proper position 
below the line A B, draw the plan of A B as 1 4 7 4 1 struck from 
the center C. Through C draw the horizontal line C 1 , and 



SHEET-METAL WORK 



19 



intersect it by a vertical line drawn from the apex C in elevation, 
fchns obtaining the apex C 1 in plan. Draw lines from 4 and 4 1 to C 1 , 
which completes the plan. 

As both halves of the scalene cone are symmetrical, it is 
necessary only to divide the half plan 14 7 into a number of equal 
spaces as shown by the small figures 1 to 7, and from points 
thus obtained draw radial lines to the apex C 1 . Then these lines 
in plan will represent the bases of triangles which will be con- 
structed, whose altitudes are all equal to D in elevation. There- 
fore in Fig. 12 draw any horizontal line, as A B, and from any 
point, as C, erect the perpen- 
dicular line C C 1 equal in 
height to D C in Fig. 11. 
Now from C 1 in plan take the 
various lengths of the lines 1 
to 7 and place them on the 
line A B in Fig. 12, measur- -? A 
ing in every instance from 
the point C, thus obtaining 
the intersections 1 to 7, from 
which lines are drawn to the 
apex C 1 . Then these lines will 
represent the true lengths of 
similarly numbered lines in 
plan in Fig. 11. 

For the pattern proceed as is shown in Fig. 13. With C as 
center and radii equal to C 1 7, 6, 5, 4, etc., in Fig. 12, describe the 
arcs 7-7, 6-6, 5-5, 4-4, etc., in Fig. 13 as shown. Now assuming 
that the seam is to come on the short side of the cone, as C B in 
Fig. 11, set the dividers equal to one of the equal spaces in 
the plan; and starting on the arc 7-7 in Fig. 13, step from arc 7 to 
arc 6, to arcs 5, 4, 3, 2, and 1, and then continue to arcs 2, 3, etc., 
up to 7. Trace a line through these intersections as shown by 
7-1-7, and draw lines from 7 and 7 to C, which completes the 
pattern. 

Now to prove that any section of an oblique or 6calene cone 
cut parallel to its base, has a similar shape to its base (differing in 
size), draw any line as a h in Fig. 11 parallel to A B. From C in 




20 



SHEET METAL WORK 



plan erect a vertical line intersecting the base line A B at d, from 
which draw a line to the apex C, cutting the line a b at e. Then 
the distances e a and e b will be equal; and using e as a center and 
e b as radius, describe the circle afbi, which is the true section 

on a b. Then «J BA 
will be the frustum of 
a scalene cone. Extend 
the line a b parallel to 
A D, cutting the diagram 
of triangles in Fig. 12 
from a to b. Then with 
radii equal to the dis- 
tances from C 1 to the 
various intersections on 
the line a &, and using 
C in Fig. 13 as center, 
intersect similarly num- 
bered radial lines drawn 
B from 7 to 1 to 7 to the 
apex C. A line [traced 
as shown from 7' tol' 
to 7' will be the desired 
cut, and 7-7-7 '-7' will 
be the pattern for the 
N frustum. The practical 
use of this method is 
shown in diagram V in 
Fig. 11; a' is the frus- 
tum of the oblique cone, 
on the ends of which are 
connected round pipes 
Fig. 1L * V and<?'. 

It is shown in Fig. 14 how in an irregular solid whose base is 
square and top is round, both top and bottom on horizontal planes 
are developed. The corners in plan F B G, GCH, H D E and 
E A F should be considered as sections of scalene cones. Proceed 
by drawing the plan A B C D 3| inches square, which represents the 




SHEET-METAL WORK 21 

plan of the base of the article; and the circle EFGH 2$ inches 
in diameter, which shows the plan of the top of the article; the 
vertical height to be 3 inches, shown from a to b. As the circle is in 
the center of the square, making the four corners symmetrical, it is 
necessary only to divide the one-quarter circle into a number of 
equal parts as shown by the small figures 1, 2, 2, 3, from which draw 
lines to the apex B. Complete the elevation as shown by I J K L. 
Now using B as center, and radii equal to B 1 and B 2 in plan, 
describe arcs intersecting A B at 1' and 2' as shown. From these 
points erect perpendiculars intersecting the top of the article I J 



/' 



S 



'!>'' 






/ 



/ 



\> 



A 



HALF PATTERN" 



K 



— t. 



/ 



in elevation at 1" and 2*, from which draw lines to K. Then K 1 # 
and K2" will be the true lengths of the lines shown in plan by 
B 1 and B 2 respectively on the finished article. 

For the half pattern proceed as follows: In Fig. 15 draw any 
horizontal line, as A B, equal in length to A B in plan in Fig. 14. 
Now with K 1" as radius and A and B in Fig. 15 as centers, describe 
arcs intersecting each other at 1 From 1 drop a vertical line 
intersecting A B at K. Then 1 K should equal J K in elevation 
in Fig. 14, which represents the true length through G N in plan. 



H 8H11T-METAL WORK 

Now with radii equal to K 1* and K 2" in elevation, and with B in 
Fig. 15 as center, describe the arcs 1-1' and 2-2'. Now set the 
dividers equal to one of the spaces in G F in plan in Fig. 14; and 
starting at 1 in Fig. 15, step off arcs having similar numbers as 
shown by 1, 2, 2', 1'. Now nsing 1 B as radius, and 1' as center, 
describe the arc B C, and intersect it by an arc struck from B as 
center and with B A as radius, as shown at O. Take a tracing of 1 
B 1' and place it as shown by 1' 01". Now connect the various 
Intersections by drawing lines from 1 to A to B to C to 
l'tol' to 1, which completes the half pattern. The triangu- 
lar pieces 1 A B or 1 ' B C will represent the flat sides of the 
article shown in plan by 1 A B or 3 B C respectively in Fig. 14; 
and the cone patterns 1-1' B and 1-1* C in Fig. 15, the sections of 
the scalene cones 1-3-B and H-Gr-C respectively in plan in Fig. 14. 
This same rule is applicable whether the top opening of the article 
is placed exactly in the center of the base or at one side or corner. 
Various problems of this nature will arise in Practical Workshop 
Problems; and if the principles of this last problem are thoroughly 
understood, these will be easily mastered. 

Approximate Developments. In developing the blanks or 
patterns for sheet-metal work which requires that the metal be 
hammered or raised by hand, or passed between male and female 
dies in foot or power presses, circular rolls, or hammering machines, 
the blanks or patterns are developed by the approximate method, 
because no accurate pattern can be obtained. In all raised or 
pressed work in sheet metal, more depends upon the skill that the 
workman has with the hammer, than on the patterns, which are but 
approximate at their best. While this is true, it is equally true 
that if the workman understands the scientific rule for obtaining 
these approximate patterns a vast amount of time and labor can be 
saved in bringing the metal to its proper profile. If the true rule 
for averaging the various shapes and profiles in circular work is not 
understood, the result is that the blank has either too little or too 
great a flare and will not form to its proper profile and curve. 
Before proceeding to describe the approximate development 
methods s attention is called to the governing principle underlying 
all such operations. We have previously shown how the patterns 
are developed for simple flaring ware; in other words, how to 



SHEET-METAL WORK 23 

develop the frustum of a cone. The patterns for curved or any 
other form of circular or hammered work are produced upon the 
same principle. The first illustration of that principle is shown in 
Fig. 16, in which A B D represents a sphere 3 inches in diameter 
composed of six horizontal sections, struck from the center a. 




Fig. 16. 

Divide the quarter circle A C into as many parts as there are 
sections required in the half sphere (in this case three), and draw 
horizontal lines through the ball as shown. The various radii for 
the patterns are then obtained by drawing lines through O b, b e y 
and o A. Thus b extended meets the center line E D at e, which 



U SHEET-METAL WORK 

is the center for striking the blank for number 3, using the radii 
e b and e C. In similar manner draw a line from h to c, extending 
it until it meets E D at d. Then d c and d h will be the radii for 
blank number 2, while A c is the radius for blank 1 shown at S. 
The lengths of the pattern pieces are determined in the same 
manner as would be the case with an ordinary flaring pan in 
producing the patterns for tin ware, and will be explained 




PLAN 



big. 17. 



thoroughly in the Practical Workshop Problems which will 
shortly follow. 

In Fig. 17 is shown another elevation of a sphere composed of 
twelve vertical sections as shown in plan view. While the method 
used for obtaining the pattern is by means of parallel lines, and 
would be strictly accurate if the sections in plan remained straight 
as from 4 to 4, the pattern becomes approximate as soon as we start 
to raise it by means of machine or hammer to conform to the profile 
B in elevation, because the distance along the curve a from 4' to4 f 



SHEET-METAL WOB& 



in plan is greater than a straight distance from 4 to 4. The patera 
by this method is obtained as follows : Let B represent the elevation 
of the sphere, and A the plan of the same, which is divided into as 
many sides as the sphere is to have vertical sections, in this case 
12, being careful that the two opposite sides 4-4 and 4' 4' in plan 
run parallel to the center line as shown. Make the diameter of the 

sphere 4-4" 3 inohes. 
Divide the half ele- 
vation into an equal 
number of spaces as 
shown from 1 to 4 to 
1, and from these 
points drop lines at 
right angles to 4-4* 
intersecting the mi- 
ter lines 1-4 in plan 
as shown. Now draw 
any horizontal line, 
as 1 '-1 ', upon which 
place the stretchout 
of 1-4-1 in elevation 
as shown by l'-4 f - 
l'onthelinel'-l' 
inO. Through these 
points draw lines at 
right angles to 1'- 
1', which intersect 
by lines drawn from 
similarly numbered 
intersections on the 
Fig. 18. miter lines 1-4 in 

plan, at right angles to 4-4. A line traced through points thus 
obtained as shown by C will be the desired pattern. 

In Fig. 18 is shown the principle used in obtaining the radii 
with which to develop the blank for a curved or circular mould 
when it is to be hammered by hand. In this connection, only the 
principle employed will be shown, leaving the full development and 
also the development for patterns which are to be raised by hand 




SHEET-METAL WORK 



and hammered by machine, to be explained in problems which "will 
follow in Practical Workshop Problems. Draw this problem double 
the size shown. First draw the elevation A B C D, and through 
the elevation draw the center line F G. Then using G as a center, 
draw the circles A 1 B 1 and C 1 D 1 representing respectively the 
horizontal projections of A B and C D in elevation. Now draw a 
line from A to E in elevation, connecting the corners of the cove 
as shown. Bisect A E and obtain the point H, from which at right 
angles to A E draw a line intersecting the cove at J. Through J 
parallel to A E draw a line intersecting the center line F G at M. 
Take the stretchout from J to A and from J to E and place it on 
the line J M as shown respectively from J to L and from J to K. 
Then will M L and MK be the radii with which to strike the 
pattern or blank for the cove. From J drop a vertical line intersect- 
ing the line D 1 G in plan at N. Then with G as center strike the 
quarter circle N O. Now using M as center and M J as radius, 
strike the arc J P. Then on this arc, starting from J, lay off 4 times 
the stretchout of N O in plan for the full pattern. It should be 
understood that when stretching the cove A E, the point J remains 
stationary and the metal from J to L and from J to K is hammered 
respectively toward J A and J E. For this reason is the stretchout 
obtained from the point J. 

PRACTICAL WORKSHOP PROBLEMS. 

In presenting the 32 problems which follow on sheet-metal 
work, practical problems have been selected such as would arise in 
every-day shop practice. 

In this connection we wish to im- 
press upon the student the necessity of 
working out each and every one of the 
32 problems. Models should be made 
from stiff cardboard, or, if agreeable to 
the proprietor of the shop, the patterns 
can be developed at home, then cut out 
of scrap metal in the shop during 
lunch hour, and proven in this way. Fig. 19. 

Our first problem is shown in Fig. 19, and is known as a sink 
drainer. It is often the case that the trap under the kitchen sink 




SHEET-METAL WORK 



is choked or blocked, owing to a collection of refuse matter. To 
avoid this a sink drainer is used, and is fastened in position through 
the wire loops «, h and c. The refuse matter is poured into the 
drainer, from which it is easily removed after the fluid has passed 
through the perforations. These drainers may be made of tin or of 
black or galvanized iron, but where a good job is wanted 16-ounce 
copper should be used. To obtain the pattern for any sized drainer, 

proceed as follows: First draw the 
plan of the drainer A B in Fig. 20, 
making A B and B C each two inches 
and forming a right angle. Then 
using B as center and A B as radius, 
draw the arc A C. In its proper posi- 
tion above the plan construct the side 
elevation, making E D 2 inches high, 
and draw the line F D. Then will 
FEDbe the side elevation. Divide 
the arc A into equal spaces as shown 
by the small figures 1 to 5. For the 
pattern use F D as radius, and with 
B D in Fig. 21 as center strike the arc 
1 5. From 1 draw a line to D and 
step off on 1-5 the same number of 
spaces as contained in A in plan in 
Fig. 20, as shown by similar figures 
in Fig. 21. Draw a line from 5 to D. 
Then will 1-5-D be the pattern for 
the front of the strainer, in which per- 
forations should be punched as shown. 
To join the sides of this pattern, 
use 1 and 5 as centers, and with either F E or A B in Fig. 20 as 
radius, describe the arcs E and E 1 in Fig. 21. Now using D as 
center and D E in Fig. 20 as radius, intersect the arcs E and E 1 as 
shown in Fig. 21. Draw lines from 1 to E 1 to D to E to 5, which 
completes the pattern, to which edges must be allowed for wiring 
at the top and seaming at the back. 

When joining a faucet or stop cock to a sheet-metal tank it is 
usual to strengthen the joint by means of a conical "boss," which 




Fig. 20. 



SHEET-METAL WOKK 



is indicated by A in Fig. 22. In this problem the cone method is 
employed, using principles similar to those used in developing a 
frustum of a cone intersected by any line. Therefore in Fig. 23 let 




A B represent the part plan of the tank, C portion of the faucet 
extending back to the tank line, and F G H I the conical "boss" 
to fit around a faucet. When 
drawing this problem make the 
radius of the tank D A equal 
to 3| inches, and from D draw 
the vertical line D E. Make 
the distance from G to H equal 
to 2f inches, the diameter of the 
faucet F I 1| inches and the 
vertical height KC 1| inches. 
Draw a line from G to H inter- 
secting the center line D E at K. 
Then using K as center describe 
the half section G J H as 
shown. Divide J H into equal 
parts shown from 1 to 4, from lg * 

which drop vertical lines intersecting the line G H as shown, 
from which draw radial lines to the apex E cutting the plan line 




SHEET-METAL WORK 



2V 



of the tank A B as shown. From these intersections draw hori- 
zontal lines intersecting the side of the cone H I at 1, 2', 3', and 4", 
Now use E as center, and with radius equal to E 1 describe the 



V*D 




Fig. 2& 

uo 2°-*l x as s&owii. Draw a line from 1° to S, and starting i&m 
1* set off on l°-l x four times the number of spaces contained ia 



SO SHEET-METAL WORK 

J H in plan, as shown by similar numbers on 1° 1*. Draw a line 
from l x to E, and with E I as radius describe the arc N L inter- 
secting the radial lines 1° E and l x E at N and L respectively. 
From the various numbers on the arc 1° l x draw radial lines to 
the apex E; and using E as center and with radii equal to E 4', 
E 3 ' , and E 2 ' , draw arcs intersecting similarly numbered radial 
lines as shown. Trace a line through points thus obtained; then 
will N 1° 1 l x L be the pattern for the "boss." 

In Fig. 24 is shown what is known as a hip bath. In drawing 
out the problem for practice the student should remember that it is 
similar to the preceding one, the only difference being in the outline 
of the cone. Make the top of the cone I B in Fig. 25 equal to 3^ 
inches, the bottom C D If inches, the vertical height from K to 5 ' 
2^ inches, the diameter of the foot EF 2| inches, and the vertical 
height 5 '-5" £-inch. Through the center of the cone draw the 

center line K L, and at pleasure 
draw the outline of the bath as 
shown by A J B. It is imma- 
terial of what outline this may be, 
the principles that follow being 
applicable to any case. Thus, in 
the side elevation, extend the 
lines B C and A D until they 
intersect the center line at L. In 
Fig. 24. similar manner extend the sides 

of the foot piece E D and F C until they intersect the center 
line at K. Now with 5' as center and with radius equal to 5' D 
or 5 ' C, describe the half section CHD, which divide into equal 
spaces as shown by the small figures 1 to 9. From the points of 
division erect vertical lines meeting the base line of the bath D 
at points 1, 2', 3', etc., to 9. From the apex L and through these 
points draw radial lines intersecting the outline B J A, from which 
horizontal lines are drawn intersecting the side of the bath B C 
as shown from 1 to 9. For the pattern for the body use L as center, 
and with L O as radius draw the arc F IA Now starting at any 
point, as 1, set off on F L 1 twice the stretchout of D H C as shown 
by similar numbers on the arc F L 1 . From the apex L and through 
the small figures draw radial lines, which intersect by arcs 




SHEET-METAL WORK 



31 



struck from L as center with radii equal to similarly numbered 
intersections on B C. Trace a line through points thus obtained, 
and L 1 M N P F will be the pattern for the body of the bath 
to which laps should be added at the bottom and sides for seaming. 




Pig. 25. 



The pattern for the foot is obtained by using as radii R D and 
R E, and striking the pattern using R 1 as center, the half pattern 
being shown by E 1 T E 1 D 1 D 1 , and the distance D 1 D 1 being equal 
to the stretchout of the half section D H G in side elevation. 



92 SHEET-METAL WORK 

It is usual to put a bead along the edges of the top of a bath as 
shown at a and b in Fig. 24. For this purpose tubing is sometimes 
used, made of brass, zinc, or copper and bent to the required shape; 
or zinc tubes may be rolled and soldered by hand, filled with 
heated white sand or hot rosin, and bent as needed. The tube or 
bead can be soldered to the body as shown in (A) in Fig. 25. Here 
a represents the bead, in which a slot is cut as c, and which is then 
slipped over the edge of the bath and soldered. Another method 
is shown in (B), in which the bath body b is flanged over the bead 
a and soldered clean and smooth at c, being then scraped and 
sandpapered to make a smooth joint. A wired edge is shown at c 
in Fig. 24, for which laps must be allowed as shown in Fig. 25 on 
the half pattern for foot. 

In Fig. 26 is shown the perspective view of a bath tub; these 
tubs are usually made from IX tin or No. 24 galvanized iron. The 
bottom and side seams are locked and thoroughly soldered, while 

the top edge is wired with handles 
riveted in position as shown 
at A. The method used in de- 
veloping these patterns will be 
the cone method and triangula- 
Pi„ 26. Hon.. In drawing this problem 

for practice (Fig. 27), first draw the center line "W 8 in plan ; and using 
a as center with a radius equal to 1\ inches draw the semicircle 
C-12 D. Now make the distance a to b 4 inches; and using b as 
center with a radius of If inches draw the semicircle E-7-H. 
Draw lines from E to D and from C to H. D E 7 H C 12 D will 
be the plan of the bottom of the bath. In this case we assume 
that the flare between the top and bottom of the narrow end of the 
bath should be equal; therefore using a as center and with a radius 
equal to 1| inches draw the semicircle A W B. At the upper end 
of the bath the flare will be unequal; therefore from b measure a 
distance on line W 8 of 1 inch and obtain c, which use as center, 
and with a radius equal to 2 inches describe the arc F 8 Q-. Draw 
lines from F to A and from B to G; and A F 8 Gt B W A will be 
the plan of the top of the bath. Now project the side elevation 
from the plan as shown by the dotted lines, making the slant 
height from I to E 2| inches and from J to K 3£ inches ; draw a line 




SHEET-METAL WORK 



33 



from K to R, and J K R I will be the side elevation of the bath tnb. 
In constructing the bath in practice, seams are located at H G, F E, 




\ \ \ \ A V \ V 



PATTERN 

TOR A-B-OO 

IN PLAN 



\ \ xvA il 







4' 



& 



7». 



-$** 






** 



•«% 



^Bf 



"*•*_ 



A D, 



C B in plana, tlms mi 



TRlAMiL^B 



the tub in four pieces 



84 SHEET-METAL WORK 

The lower end of the bath will be developed by the cone 
method as in the last two problems. From the center a drop a line 
indefinitely as shown. Extend the side R I of the side elevation 
until it meets the center line a d at d. Now divide the quarter 
circle 12-9 in plan into equal spaces as shown by the small figures 
9, 10, 11, and 12, from which drop vertical lines (not shown) 
intersecting the bottom of the bath tub in elevation from 9' to 12'. 
Then through these points from d draw lines intersecting the top 
line of the bath R K as shown, from which draw horizontal lines 
intersecting the side I-R extended as I X at points 9" to 12". 
Then using d as center and d I as radius, describe the arc I M, 
upon which place the stretchout of D 12 C in plan, as shown 
by similarly numbered points on L M. Through these points from 
d draw radial lines, which intersect by arcs drawn from similarly 
numbered intersections on I R extended, using d as center. Trace 
a line as shown, and LMNP will be the pattern for the lower 
end of the tub A B C D in plan. Laps should be allowed foi 
wiring and seaming. 

As the patterns for the upper end and sides will be developed 
by triangulation, diagrams of triangles must first be obtained, for 
which proceed as follows: Divide both of the quarter circles H 7 
and G 8 in plan into the same number of spaces as shown respec- 
tively from 1 to 7 and from 2 to 8. Connect these numbers by 
dotted lines as shown from 1 to 2, 2 to 3, 3 to 4, etc. From the 
various points 2, 4, 6, and 8 representing the top of the bath, drop 
lines meeting the base line Z f in elevation at 2 X , 4 s , 6 X , and 8 X , 
and cutting the top line of the bath at 2', 4', 6', and 8'. Then 
will the dotted lines in plan represent the bases of the triangles, 
which will be constructed, whose altitudes are equal to the various 
heights in elevation. Take the various distances 1 to 2, 2 to 3, 
3 to 4, 4 to 5, etc., in plan up to 8, and place them on the vertical 
line l"-8" in (B) as shown from 1" to 2", 2" to 3% 3" to 4", 4" to 5", 
etc., up to 8". For example, to obtain the true length of the line 
6-7 in plan, remembering that the points having even numbers 
represent the top line of the bath and those having uneven 
numbers the base line, draw at right angles to l"-8" in (B), from 
6", a line equal in height to o^-d" in elevation, and draw a line 
from 6 V to V in (B), which is the length desired. For the true 



SHEET-METAL WOEK 35 

length of 6-5 in plan it is necessary only to take this distance 
place it from 6" to 5" in (B) and draw a line from 6 V to 5". In this 
way each altitude answers for two triangles. In plan draw a line 
from 1 to 0. Then will two more triangles be necessary, one on the 
line 1-0, and the other on B G or 0-2. From 2 ' in elevation draw 
a horizontal line, as 2' e, intersecting the vertical line dropped 
from at e. Now take the distances 1 and 2, and place them 
in (A) as shown by the horizontal lines 0"-l" and S -2 S respectively. 
At right angles to both lines at either end draw the vertical lines 
0"-0'" and 0M) V equal in height respectively to C x 0' and e0 r 
in elevation. Draw in (A) lines from 2 s to y and from 1" to 0'", 
which are the desired lengths. Before proceeding with the pattern, 
a true section must be obtained on 2 '-8' in side elevation. Take 
the various distances 2' to 8' and place them on the line 2 '-8' in 
Fig. 28. At right angles to 2 '-8' 
and through the small figures draw 
lines as shown. Now measuring in 
each and every instance from the 
center line in plan in Fig. 27, take the 
various distances to points 2, 4, and 2 l 
6 and place them on similarly num. Fig* 28 - 

bered lines in Fig. 28, measuring in each case on either side of the 
line 2 '-8', thus obtaining the intersections 2-4-6. A line traced 
through these points will be the true section on 2* -8 ' in elevation 
in Fig. 27. 

For the pattern for the upper end of the tub proceed as follows: 
Take the distance of 7"-8 v in (B) and place it on the vertical line 
7-8 in Fig. 29. Then using 8 as center and with a radius equal 
to 8 '-6 in Fig. 28, describe the arc 6 in Fig. 29, which intersect by 
an arc struck from 7 as center and with 7"-6 v in (B) in Fig. 27 
as radius. Then using 7-5 in plan as radius, and 7 in Fig. 29 as 
center, describe the arc 5, which intersect by an arc struck from 6 
as center and with 6 v -5" in (B) in Fig. 27 as radius. Proceed in 
this manner, using alternately as radii first the divisions in Fig. 28, 
then the length of the slant lines in (B) in Fig. 27, the divisions 
on 7 H in plan, then again the slant lines in B, until the line 1-2 
in Fig. 29 is obtained. Trace a line through points thus obtained, 
as shown by 2-8-7-1. Trace this opposite the line 8-7, as shown 




BHEET-METAL WORK 



by 2' 1". Then will 2-8-2'«r~7-l be the desired pattern, to 
which laps must be allowed. 

For the pattern for the side of the bath draw any line 9-1 in 
Fig. 80 equal to 9-1 in plan in Fig. 27. Now with a radios equal 




to 9-P in the pattern X and with 9 in Fig. 30 as a center, describe 
the arc 0, which intersect by an arc struck from 1 as center and 
with l"-0'" in (A) in Fig. 27 as radius. Now taking a radius equal 
to V ~2 X in (A) with in Fig. 80 as center, describe the arc 2, which 

intersect by an arc 

struck from 1 as center, 

and with 1-2 in Fig. 29 

as radius. Draw lines 

from corner to comer in 

Fig. 30, which gives 

the desired pattern, to 

which laps are added 

Pig. so. for seaming and wiring. 

In Fig. 31 is shown a perspective view of a funnel strainer 

paiL These pails are usually made from IX bright tin, and the 

same principles as are used in the development of the pattern are 




ion, 



First draw the center line O I in Fig. 82, at right anj$es to whicfe 



SHEET-METAL WORK 37 

draw H E and H F each equal to 1\ inches. Make the vertical 
freight H C 3£ inches and G D 2 inches. Now make the vertical 
heights measuring from O G, to A, and to P respectively I£ 
inohes, and 1^ inches. Make the horizontal distance from C to G 
2f inches, the diameter from G to A If inches, and from A to B 
f-inch, and draw a line from B to C. Connect points bylines; 
then will ABCDEFGbe the side elevation of the pail. In its 
proper position below F E, with J as center, draw the plan KLMK 
Also in its proper position draw the section on A G as O P B, S, 
Now draw the rear elevation making G 1 U and G 1 V each equal to 
H E, and 1" T and l'-l' each equal to C D. Project a line from 
B in side, intersecting the center line in rear at 4'. Then through 
the three points 1' 4' T draw the curve at pleasure, which in this 
case is struck from the center a. WYXZ represents the opening 
on G A in side obtained as shown by the dotted lines but having 
no bearing on the patterns. Pails 
of this kind are usually made 
from two pieces, with seams at 
the sides, as in Fig. 31. The 
pattern then for the back shown 
by C D E H in side elevation in 
Fig. 32 will be obtained by the 
cone method, struck from the 
center I, the stretchout on E 1 E 2 
in the pattern being obtained 
from the half plan. The pattern 
f or D E H is shown with lap Fig- 3L 

and wire allowances by D 1 D 2 E 2 E 1 and needs no further explanation. 
The front part of the pail shown by A B H F G will be 
developed by triangulation, but before this can be done a true 
section must be obtained on B C, and a set of sections developed 
as follows: Divide one-half of V 4' T in rear elevation into equal 
parts as shown from 1' to 4', from which draw horizontal lines 
intersecting the line B C as shown. From these intersections 
lines are drawn at right angles to B equal in length to similarly 
numbered lines in rear as 3'-3", 2'-2 ff , and l'-l". Trace a line 
as shown, so that V" 2'" 3'" 4'" will be the true half section 
onBC. To avoid a confusion of lines take a tracing of ABOHFG 




38 



SHEET-METAL WORK 



and place it as shown by similar letters in Fig. 33. Now take 
tracings of the half sections in Fig. 32, as H E D C, C V" B, 
P O S, and the quarter plan NJM, and place them in Fig. 33 on 
similar lines on which they represent sections as shown respectively 
by H 9' 8' C, C 8 B, A 3 G, and F 9 H. Divide the half section 




A 3 G into 6 equal parts as shown by the small figures 1 to 5 ; 
As this half section is divided into 6 parts, then must each of the 
sections B 8 and F 9 H be divided into 3 parts as shown respec- 
tively from 6 to 8 and 9 to 11. As C 8' and H 9' are equal 
respectively to C 8 and H 9 they are numbered the same as shown. 



SHEET-METAL WORK 



39 



Now at right angles to Gr A, B C, C H, and H F, and from the 
various intersections contained in the sections Gr 3 A, B 8 C, 
C 8' 9' H, and H 9 F, draw lines intersecting the base lines of the 
sections G A, B C, C H, and HP at points shown from 1 ' to 11 ' . 
Now draw dotted lines from B to 5' to 6' to 4' to T to E to C, 
and then from H to E to 10 ' to 2 ' , etc until all the points are 




sJlO , 
*- — J* 



Fig. 33. 



connected as shown. These dotted lines represent the bases of the 
sections whose altitudes are equal to similar numbers in the various 
sections. 

In order that the student may thoroughly understand this 
method of triangulation as well as similar methods that will follow 



SHEET-METAL WORK 



in other problems, the model in Fig. 34 has been prepared, which 
shows a perspective of Fig. 33 with the sections bent up in their 
proper positions. This view is taken on the arrow line in Fig. 83, 
the letters and figures in both views being similar. For the true 
sections on the dotted lines in E A B in Fig. 33, tale the lengths 
of the dotted lines E, E 7% V 4\ etc., and place them on the 
horizontal line in Fig. 35 as shown by similar letters and figures. 
From these small figures, at right angles to the horizontal line, 
erect the vertical heights C 8, E 3, V 7, etc., equal to similai 




Fig- 31 

vertical heights in the sections in Fig. 33. Connect these pomts 
in Fig. 35 by dotted lines as shown, which are the desired true 
distances. 

In Fig. 36 are shown the true sections on dotted lines in 
G E H F in Fig. 33, which are obtained in precisely the same 
manner, the only difference being that one section is placed inside 
of another in Fig. 36. For the pattern proceed as is shown in 
Fig. 37. Draw any vertical line as G F equal to G F in Fig. 33. 
With radius equal to G 1 and with G in Fig. 37 as center describe 
the arc 1, which intersect by an arc struck from F as center and 



SHEET-METAL W0SK & 

witharadrasequaltoFlinFig.36. Now with F 11 in Fig. 33 aft 
radius and F in Fig. 37 as center, describe the aro 11, which Is 
intersected by an aro struck from 1 as center and with 1-11 in 
Fig 36 as radius. Proceed in this manner until the line 3-9 
in Fig 37 has been obtained. Then using 8 '-9' in Fig. 33 as 
radius and 9 in Fig. 37 as center, describe the arc 8, which is 
intersected by an arc struck from 3 as center and with 3-8 in Fig. 



6 



^. 



r 






i 






^ 



E 



T 
Fig. 35. 



©i §r 



35 as radius. Now use alternately as radii, first the divisions in 
B 8 in Fig. 33, then the length of the slant lines in Fig. 35, 
the divisions in E 3 A in Fig. 33, and again the distances in 
Fig. 35, until the line B A in Fig. 37 has been obtained, which is 
obtained from B A in Fig. 33. Trace a line through points thus 
obtained in Fig. 37 as shown by A B 8 9 F G A. Trace this 
half pattern opposite the line G F. Then will B A G A 1 B 1 8* 



E 






€zw 



Fig. 3ft 



WWh 



9 1 F 9 8 be the pattern for the front half of the pail. If for 
any reason the pattern is desired in one piece, then trace one- 
half of D 1 D 2 E 8 E 1 in Fig. 32 on either side of the pattern in 
Fig. 37 as shown by the dotted lines 8' D 1 E 1 9 l and 9 E D 8. 
Allow edges for wiring and seaming. 

Fig 38 shows the method for obtaining the pattern for an 
Emerson ventilator shown in Fig. 39. 



42 



SHEET-METAL WORK 




"While the regular Emerson ventilator has a flat disc for a 
hood it is improved by placing a cone and deflector on the top 
as shown. To make the patterns, proceed as shown in Fig. 38. 
First draw the center line a h, on either side of which lay off 



SHEET METAL WORK 



43 



1^ inches, making the pipe A, 3 inches in diameter. The rule 
usually employed is to make the diameter of the lower flare and 
upper hood twice the diameter of the pipe. Therefore make the 
diameter of s d 6 inches. From * and 
d, draw a line at an angle of 45° to inter- 
sect the line of the pipe at t and i; this 
completes B. Measure 2 inches above 
the line t i and make u m the same 
diameter as s d. Draw the bevel of the 
deflector so that the apex will be ^ inch 
above the line t i and make the apex 
of the hood the same distance above u m 
as the lower apex is below it. Then draw 
lines as shown which complete C and D. FJ g- 39. 

Now with g as a center and radii equal to c e and c d draw the 
quarter circles ef and d h respectively, which represent the one- 





v \ HALF PATTERN 

^x FOR 

4\\\ HOOD AND DEFLECTOR 



Fig. 38. 




Fig. 40. 



quarter pattern for the horizontal ring closing the bottom of the 
lower flare. For the pattern for the hood, use I as a center and 
I m as a radius. Now draw the arc mm'. Take the stretchout 



BHEET-ME'/AL WORK 



of the quarter circle 1 to 6 on d h, and place twice this amount 
on m m' as shown from 1-6-1. Draw a line from 1 to I. Then 
m' 6 ml, will be the half pattern for the hood. As the deflector 
has the same bevel as the hood, the hood pattern will also answer 
for the deflector,, 

When seaming the hood and deflector together as shown at 
», the hood o is double-seamed to the deflector at r, which allows 
the water to pass over; for this reason allow a double edge on 
the pattern for the hood as shown, while on the deflector but a 
single edge is required. Edges should also be allowed on e d hf» 

For the pattern for the lower flare, extend the line d i until it 
intersects the center line at j. Then with radii equal to„« i and j d 
and with j in Fig. 40 as center describe the arcs i i' and dd\ 
On one side as d draw a line to j. Then set off on the arc d d* 





Pig. 41 



Fig. 42. 



vwice the number of spaces contained in d h in Fig. 88 as shewn 
in Fig. 40. Draw a line from d' to i and allow edges for seaming. 
Then dd' i' i will be the halt pattern for the lower flare. 

The braces or supports E and F, Fig. 38, are usually made of 
galvanized band [iron bolted or riveted to hood and pipe. The 
hood D must be water tight, or the water will leak into the deflector, 
from which it will drip from the apex inside the building. 

Elbows. There is no other article in the sheet-metal worker's 
line, of which there are more made in practioe than elbows. On this 
account rules will be given for constructing the rise of the miter 
line in elbows of any size or diameter, also for elbows whose 
sections are either oval, square or round, including tapering elbows 
Before taking up the method of obtaining the patterns, the rule 
Will be giyen for obtaining the rise of the miter line for any size 



SHEET-METAL WORK 



or number of pieces. No matter how many pieces an elbow has, 
they join together and form an angle of 90°. Tims when we speak 
of a two-pieced, three-pieced, four, five or six-pieced elbow, we 
understand that the right-angled elbow is made up of that number 
of pieces. Thus in Fig. 41 is shown a two-pieced elbow placed in 
the quadrant C B, which equals 90° and makes C A B a right 
angle. From A draw the miter line A a at an angle of 45° to the 
base line A B. Then parallel to A B and A C and tangent to the 
quadrant at C and B draw lines to intersect the miter line, as 
shown. Knowing the diameter of the pipe as C D or E B draw 
lines parallel to the arms of the pipe, as shown. Then C B E D 
will be a two-pieced elbow, whose miter line is an angle of 45°. 

In a similar manner draw the quadrant B C, Fig. 42, in which 
it is desired to draw a three-pieced elbow. Now follow this simple 





Fig. 43. 

rule, which is applicable for any number of pieces: Let the top 
piece of the elbow represent 1, also the lower piece 1, and for every 
piece between the top and bottom add 2. Thus in a three-pieced 
elbow: 

Top piece equals 1 

Bottom piece equals 1 

One piece between 2 

Total equals 4 

Now divide the quadrant of 90° by 4 which leaves 22| e . As 
one piece equals 22^°, draw the lower miter line A a at that 
angle to the base line A B. Then as the middle piece represents 
two by the above rule and equals 45°, add 45 to 22-§ and draw the 
second miter line A 5, at an angle of 67^° to the base line A B. 
Now tangent to the quadrant at C and B draw the vertical and 



4& 



SHEET-METAL WORK 



horizontal lines shown, until they intersect the miter lines, from 

which intersections draw the middle line, which will be tangent to 

the quadrant at F. CD and B E show the diameters of the pipe, 

which are drawn parallel to the lines of the elbow shown. 

Fig. 43 shows a four-pieced elbow, to which the same rule is 

applied. Thus the top and bottom piece equals 2 and the two 

middle pieces equal 4; total 6. Now divide the quadrant of 90° by 

90 
6. — x = 15. Then the first miter line A a will equal 15°, the 
o 

second A b 45°, the third A c 75°, and the vertical line A C 90°. 

The last example is shown in Fig. 44, which shows a five- 
pieced elbow, in which the top and bottom pieces equal 2, the 3 

90 



middle pieces 6; total 8. Divide 90 by 8. 



= 11^. Then the 



first miter line will equal 11^°, the second 33|°, the third 56|°,and 

the fourth 78|°. By 
using this method an 
elbow having any num- 
ber of pieces may be 
laid out. When draw- 
ing these miter lines it 
is well to use the pro- 
tractor shown in Fig. 45, 
which illustrates how to 
lay out a three-pieced 
elbow. From the center 
point A of the protrac- 
tor draw lines through 
22|°,and67|°. Now set 
off A a, and the diameter of the pipe a b. Draw vertical lines 
from a and b to the miter line at c and d. Lay off similar distances 
from A to a' tob' and draw horizontal lines intersecting the 67|° 
miter line at c' and d' . Then draw the lines d d' andcc' to 
©omplete the elbow. In practice, however, it is not necessary to 
draw out the entire view of the elbow; all that is required is the 
first miter line, as will be explained in the following problems. 




SHEET-METAL WORK 



47 



EXERCISES FOR PRACTICE. 

1. Make the diameter of the pipe If inches and the distances 
from A to E 1^ inches in Figs. 41 to 44 inclusive. 

To obtain the pattern for any elbow, using but the first miter 





Fig. 46. 

line, proceed as follows: In Fig. 46 let A and B represent respect- 
ively a two- and three-pieced elbow for which patterns are desired. 
First draw a section of the elbow as shown at A in Fig. 47 which 




Fig. 47. 

is a circle 3 inches in diameterj divide the lower half into equal 
spaces and number the points of division 1 to 7. Now follow the 
rule previously given: The top and bottom piece equals 2; then 



48 



SHEET-METAL WORK 



for a two-pieced elbow divide 90 by 2. In its proper position below 
the section A draw BODE making ED 45°. From the various 
points of intersection in A drop vertical lines intersecting EDus 




Fig. 48. 

shown. In line with B draw K L upon which place twice the 
number of spaces contained in the seotion A as shown by similar 
figrares oaEL; from these points drop perpendiculars to intersect 



SHEET-METAL WORK 49 

with lines drawn from similar intersections on E D, parallel to K L. 
Trace a line through points shown; then KLONM will be 
the pattern. To this laps must be allowed for seaming. 

Now to obtain the pattern for a three-pieced elbow, follow the 
rule. Top and bottom pieces equal 2, one middle piece equals 2; 

90 
total 4. — -j = 22|. Therefore in line with the section A below 

the two-pieced elbow draw FGJH, making H J at an angle of 
22§° to the line H h. Proceed as above using the same stretchout 
lines; then UPRST will be the desired pattern. It should be 
understood that when the protractor is used for obtaining the angle 
as shown in Fig. 45, the heights a o and b d measured from the 
horizontal line form the basis for obtaining the heights of the 
middle pieces, inasmuch as they represent one-half the distance; 
for that reason the middle pieces count 2 when using the rule. 
Therefore, the distances F H and G J (Fig. 47), represent one-half 
of the center piece and UTSRP one-half the pattern for the 
center piece of a three-pieced elbow. 

Fig. 48 shows how the patterns are laid into one another, to 
prevent waste of metal when cutting. In this example we have a 
three-pieced elbow whose section is 2 X 2 inches. It is to be laid 
out in a quadrant whose radius is 5 inches. Use the same 
principles for square section as for round; number the corners of 
the section 1 to 4. In line with S t draw D E upon which place 
the stretchout of the square section as shown by similar numbers 
on D E; from which draw horizontal lines which intersect lines 
drawn parallel to D E from the intersections 1' 2' and 3' 4' in A 
in elevation, thus obtaining similar points in the pattern. Then 
A 1 will be the pattern for A in elevation. For the pattern for B 
simply take the distance from 2' toj and place it on the line 4 4' 
extended in the pattern on either side as shown by 4' 4" on both 
sides. Now reverse the cut 4' 2' 4' and obtain 4" 2" 4*. By 
measurement it will be found that 4' 4" is twice the length of 2' 2 
as explained in connection with Figs. 45 and 47. Make the distance 
from 1* to a' the same as j to a in C and draw the vertical line 
V V intersecting the lines 44" extended on both sides. Then A 1 t B l , 
and C* will be the patterns in one piece minus the edges tor 



50 



SHEET-METAL WORK 



seaming which must be allowed between these cuts ; this would of 
course make the lengths b' 4", 4" 4' and 4' 4 as much longer as 
the laps would necessitate. 

This method of cutting elbows in one piece, from one square 
is applicable to either round, oval or square sections. 

In Figs. 49 and 50 are shown three-pieced elbows such as are 





Fig. 49. 



Fig. 50. 



rs 



\JL.. 



used in furnace-pipe work and are usually made from bright tin. 
Note the difference in the position of the sections of the two 
elbows. In Fig. 49 a b is in a vertical position, while in Fig. 50 it 
is in a horizontal position. In obtaining the patterns the same 

rule is employed as in pre- 
vious problems, care being 
taken when developing the 
patterns for Fig. 49 that 
the section be placed as in 
Fig. 51 at A; and when 
developing the patterns for 
Fig. 50, that the section be 
placed as shown at A in 

Fig. 51. Fig. 53 shows a taper- 

ing two-pieced elbow, round in section. The method here shown 
is short and while not strictly accurate, gives good results. 
It has been shown in previous problems on Intersections and 
Developments that an oblique section through the opposite 




SHEET-METAL WORK 



§1 



sides of a c<5ne is a true ellipse. Bearing this in mind it is 
evident that if the frustum of the cone H I O N, Fig. 54, were 
a solid and cut obliquely by the plane J K and the several parts 
placed side by side, both would present true ellipses of exactly the 
same size, and if the two parts were placed together again turning 
the upper piece half-way around as shown by J W M K, the edges 




Pig. 52. 

of the two pieces from J to K would exactly coincide. Taking 
advantage of this fact, it is necessary only to ascertain the angle of 
the line J K, to produce the required angle, between the two pieces 
of the elbow, both of which have an equal flare. The angle of the 
miter line, or the line which cuts the cone in two parts, must be 
found accurately so that when joined together an elbow will 
be formed having the desired 
Angle on the line of its axis. 
Therefore draw any vertical 
line as A B. With C as a center 
describe the plan of the desired 
diameter as shown by E D F B. 
At right angles to A B draw the 
bottom line of the elbow H I 
equal to E F, or in this case, 3 
inches. Measuring from the line 




Fig. 53. 



H I on the line A B the height of the frustum is 5 inches. 
Through X' draw the upper diameter O N, 1% inches. Extend the 
contour lines of the frustum until they intersect the center line 
at L. Divide the half plan E D F into a number of equal parts 
as shown; from these points urect lines intersecting the base lin© 
H I from which draw lines to the apex L. As the elbow is to ha 
in two pieces, and the axis at right angles, draw the angle TBS, 



52 



SHEET-METAL WORK 



bisect it at U and draw the line R V. No matter what the angle of 
the elbow, use this method. Now establish the point J at some 
convenient point on the cone, and from J, parallel to R V, draw the 
miter line J K intersecting the radial lines drawn through the cone; 
from these points and at right angles to the center line A B draw 
lines intersecting the side of the cone J H from 1 to 7. If it is 







Fig. 54. 

desired to know how the side of the tapering elbow would look, 
take a tracing of N O K J s reverse it and place it as shown by 
JWMK 

For the pattern proceed as follows: With L as a center and 
LHasa radius describe the arc 1 1. Starting from 1 set off on 



SHEET-METAL WORK 5S 

this arc twice the stretchout of 1 4 7 in plan, as shown by similar 
figures on 1 1, from which draw radial lines to the apes L, Again 
using L as center with radii equal to L N, L 1, L 2 to L 7, draw arcs 
as shown intersecting radial lines having similar numbers. Through 
these intersections draw the line J' I/. Then O' N' J' K' L' 
or A will be the pattern for the upper arm (A) in elevation, and 
P ' R ' T ' X Y or B the pattern for the lower arm (B) in elevation. 




Fig. 55. 

The pattern should be developed full size in practice and then 
pricked from the paper on to the sheet metal, drawing the two 
patterns as far apart as to admit allowing an edge to A at a; also 
an edge at b to B for seaming. 

When a pattern is to contain more than two pieces the method 
of constructing the miter lines in the elevation of the cone is 



54 



SHEET-METAL WORK 



slightly different as shown in Fig. 55. Assume the bottom to be 
3 inches in diameter and the top 1\ inches. Let the vertical height 
be 4 inches. In this problem, as in the preceding, the various 
pieces necessary to form the elbow are cut from one cone whose 
dimensions must be determined from the dimensions of the required 
elbow. The first step is to determine the miter lines, which can 
be done the same as if regular pieced elbows were being developed. 
As the elbow is to consist of four pieces in 90°, follow the rule 
given in connection with elbow drafting. The top and bottom 

90 
piece equal 2; the two middle pieces equal 4; total 6. — « = 15. 

Lay offABCD according to the dimensions given, and draw the 
half plan below D C; divide it into equal parts as shown. Prom 
the points of division erect perpendiculars intersecting D C, from 
which draw lines meeting the center line E 4 at F. 





a-lo-c 
SLIGHT BENDS 



Pig. 56. 



Fig. 57. 



We assume that the amount of rise and projection of the elbow 
are not specified, excepting that the lines of axis will be at right 
angles. Knowing the angle of the miter line, it becomes a matter 
of judgment upon the part of the pattern draftsman, what length 
shall be given to each of the pieces composing the elbow. Therefore 
establish the points G, I and K, making D G, G I, I K and K A 
|, 1£, f and 1 inch respectively. From G, I and K draw the hori- 
zontal lines G 1", I 1° and K l x . To each of these lines draw the 
lines G H, I J and K L respectively at an angle of 15° intersecting 
the radial lines in the cone as shown. From these intersections 
draw horizontal lines cutting the side of the cone. Then using F 
as a center, obtain the various patterns O, P, K and S in the 
manner already explained. 



SHEET-METAL WORK 



In Fig. 56 is shown a side view of the elbow, resulting from 
preceding operations; while it can be drawn from dimensions 
obtained in Fig. 55, it would be impossible to draw it without first 
having these dimensions. 

In Fig. 57 is shown a perspective view of a tapering square 
elbow of square section in two pieces. This elbow may have any 
given taper. This problem will be developed by triangulation and 
parallel lines; it is an interesting study in projections as well as 
in developments. First draw the elevation of the elbow in Fig. 58 
making 1-6 equal to 3^ inches, the vertical height 1-2, 4| inches, 
and 6-5, 2^ inches; the projection between 1 and 2 should be 
§ inch and between 5 and 6, § inch. Make the horizontal distance 



elevation _ J? 







PLAN °' ° OEVELOPEMENTS 

Fig. 58. 

from 5 to 4, 2 inches, and the rise at 4 from the horizontal line 
\ inch, and the vertical distance from 4 to 3, 1\ inches. Then draw 
a line from 3 to 2 to complete the elevation. 

In its proper position below the line 1-6, draw the plan on 
that line, as shown by 1' V 6' 6'. Through this line draw the 
center line A B. As the elbow should have a true taper from 1 to 3 
and from 4 to 6, we may develop the patterns for the top and 
bottom pieces first and then from these construct the plan. There- 
fore, take the distances from 1 to 2 to 3 and from 4 to 5 to 6 in 
elevation and place them on the line A B in plan as shown respec- 
tively from 1° to 2° to 3° and from 4° to 5° to 6°; through these 
points draw vertical lines as shown. While the full developments 



56 SHEET-METAL WORK 

E and D are shown we shall deal with but one-half in the explana- 
tion which follows. As the elbow is to have the same taper on 
either side, take the half distance of the bottom of the elbow 1-6 
and place it as shown from l°-6° to l"-6", and the half width of 
the top of the elbow 3-4 and place it as shown from 3° to 3" and 4° 
to 4". Then draw lines from 3" to 1" intersecting the bend 2° at 
2", and a line from 4" to 6" intersecting the bend 5° at 5". Trace 
these points on the opposite side of the line A B. Then 1" 3" a b 
will be the pattern for the top of the elbow and 6" 4" o b the 
pattern for the bottom. From these various points of intersection 
draw horizontal lines to the plan, and intersect them by lines 
drawn from similarly numbered points in the elevation at right 
angles to A B in plan. Draw lines through the points thus 
pat tern for obtained in plan as shown by 1 ' , 2 ' , 3 ' , 4 ' , 

5 ' and 6 ' which will represent the half plan 
view. For the completed plan, trace these 
lines opposite the line A B as shown. It 
will be noticed that the line 3-4 in eleva- 
tion is perpendicular as shown by 3' 4' 
in plan while the points 2 ' and 5 ' project 
from it, showing that the piece 2-3-4-5 
Fig. 59. in elevation must be slightly twisted 

along the line 5-3 when forming the elbow. Similarly slight 
bends will be required along the lines 1-5 and 5-2. 

It will now be necessary to obtain the true lengths or a 
diagram of triangles on the lines 1-5, 5-2 and 5-3. Connect similar 
numbers in plan as shown from 1' to 5', 5' to 2' and 5' to 3', the 
last two lines being already shown. From similar points in eleva- 
tion draw horizontal lines as shown by 2-h, 3-f, 5-e and &-d. 
Take the distances from 1' to 5', 5' to 2' and 5' to 3' in plan and 
place them on one of the lines having a similar number in eleva- 
tion, as shown respectively by l x 5 X , 5 X 2 X and 5 X 3 X . From the 
points marked 5 X draw vertical lines intersecting the horizontal 
line drawn from 5 at 5 V , 5 L and 5 P respectively. Now draw the true 
lengths 1 X 5 V , 2 X 5 L , and 3 X 5 P . For the pattern draw any line as 
1-6 in Fig. 59 equal to 1-6 in Fig. 58. Now with 6" 5" in D as a 
radius and 6 in Fig. 59 as a center, describe the arc 5 which is 
intersected by an arc struck from 1 as a center and the true length 




SHEET-METAL WORK 67 

l x 5 V in Fig. 58 as radius. Then using the true length 5 L 2* as 
radius and 5 in Fig. 59 as center, describe the arc 2, which is 
intersected by an arc struck from 1 as center and V 2" in E in 
Fig. 58 as radius. Using the true length 5 P 3 X as radius and 5 in 
Fig. 59 as center, describe the arc 3, and intersect it by an arc 
struck from 2 as center and 2" 3" in E in Fig. 58 as a radius. Now 
with 5* 4" in D as a radius and 5 in Fig. 59 as a center, describe 
tht arc 4, and intersect it by an arc struck from 3 as center and 
3-4' in the elevation in Fig. 58 as a radius. Draw lines from point 
to' point in Fig. 59 to complete the pattern. Laps should be 
allowed on all patterns, for seaming. Slight bends will take place 
as shown on the pattern, also as is shown by a b and c in Fig. 57. 
If the joint is to be on the line 2-5 in elevation in Fig. 58, the 
necessary pieces can be joined together. 

In Fig. 60 is shown a perspective view of a five-piece tapering 
elbow, having a round base and an elliptical top. This form is 

generally known as a ship ventilator. 
The principles shown in this problem 
are applicable to any form or shape no 
matter what the respective profiles may 
be at the base or top. The first step is 
to draw a correct side view of the elbow 
as shown in Fig. 61. The outline A 
BCDEP can be drawn at pleasure, 
but for practice, dimensions are given. 
First draw the vertical line A F 
equal to A\ inches. On the same 
Fig. 60. line extend measure down 1 \ inches to 

/and draw the horizontal line H B. From/" set off a distance of 
1\ inches at Gr, and using G as a center and GrPas a radius 
describe the arc F E intersecting H B at E, from which draw the 
vertical line E D equal to 1 inch. Draw D C equal to If inches, 
then draw C B. From B lay off 5| inches, and using this point (H) 
as a center and H B as a radius describe the arc B A. The portion 
shown B E D is a straight piece of pipe whose section is shown 
by I J K L. Now divide the two arcs B A and E F into the same 
number of parts that the elbow is to have pieces (in this case four) 
and draw the lines of joint or miter lines as shown by U V, etc 




m 



SHEET-METAL ^ORK 



Bisect each one of the joint lines and obtain the points abed and e. 
Then A B C D E F will be the side view. 

The patterns will be developed by triangulation, but before 
this can be done, true sections must be obtained on all of the lines 
in side elevation. The true sections on the lines B E and C D are 
shown by I J K L. The length of the sections are shown by the 
joint lines, but the width must be obtained from a front outline of 
the elbow, which is constructed as follows: In its proper relation 
to r the side elevation, draw the center line M K upon which draw 




Fig. 61. 

the ellipse M N O P (by methods already given in Mechanical 
Drawing) which represents the section on A F in side. Take half 
the diameter I K in section and place it on either side of the center 
line M R as R T or K S. Then draw the outline O S and T N in 
a convenient location. While this line is drawn at will, it should 
be understood that when once drawn, it becomes a fixed line. Now 
from the various intersections abed and e in the side elevation, 
draw lines through and intersecting the front outline as shown on 



SHEET-METAL WORK 



59 



one side by O, b\ <?', d' and e'. Then these distances will repre- 
sent the widths of the sections shown by similar letters in side. 
For example, the method will be shown for obtaining the true 



section on U V, and the pattern for piece 1 in side 
elevation. To avoid a confusion of lines take a 
tracing of A F V U and place it as shown by 1, 
13, 12, in Fig. 62. On 1-13 place the half profile 
M N P of Fig. 61. Bisect 0-12 in Fig. 62 and 
obtain the point 6 ; at a right angle to 0-12 from 6 
draw the line 6 6' equal to V h" in front outline in 
Fig. 61. Then through the three points O, 6' and 
12 in Fig. 62, draw the semi-ellipse, which will 
represent the half section on U V. The other 



4S! 



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H 



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sections on the joint lines in side elevation are v 
obtained in the same manner. 

If the sections were required for piece 2 in 
side it would be necessary to use only O 6 ' 12 in 
Fig. 62 and place it on U V in Fig. 61, and on a 
perpendicular line erected from c, place the width 
c' c" shown in front and through the three points 
obtained again draw the semi-elliptical profile or 
section. Now divide the two half sections (Fig. 62) 
into equal parts as shown by the small figures, from 
which at right angles to 1-13 and 0-12 draw lines 
intersecting these base lines from 1-13. Connect opposite points 
ae 1 to 2 to 3 to 4 to 5, etc., to 12. Then these lines wiU represent 



<» 



<& 



to 



s 



o 



M 



60 SHEET-METAL WORK 

the bases of sections whose altitudes are equal to the heights in 
the half section. For these heights proceed as follows: 

Take the various lengths from 1 to 2, 2 to 3, 3 to 4, 4 to 5, etc., 
to 11 to 12 and place them on the horizontal line in Fig. 63 as 
shown by similar figures; from these points erect vertical lines 
equal in height to similar figures, in the half section in Fig. 62 as 
shown by similar figures in Fig. 63. For example: Take the dis- 
tance from 7 to 8 in Fig. 62 and place it as shown from 7 to 8 in 
Fig. 63 and erect vertical lines 7-7', and 8-8' equal to 7-7' and 
8-8' in Fig. 62. Draw a line from 7' to 8' in Fig. 63 which is the 
true length on 7-8 in Fig. 62. For the pattern take the distance of 
l-O and place it as shown by 1-0 in Fig. 64. Now using O as a 
center and O 2' in Fig. 82 as a radius, describe the arc 2 in Fig. 64 




Fig. 64. 



and intersect it by an arc struck from 1 as a center with 1-2' in 
Fig. 63 as a radius. Now with 1-3' in Fig. 62 as a radius and 1 in 
Fig. 64 as a center, describe the arc 3, and intersect it by an arc 
struck from 2 as center and 2'-3' in Fig. 63 as a radius. Proceed 
thus, using alternately as radii, first the divisions in 0-6-12 in 
Fig. 62, then the proper line in Fig. 63, the divisions in 1-7-13 in 
Fig. 62 and again the proper line in Fig. 63, until the line 12-13 
in Fig. 64 is obtained, which equals 12-13 in Fig. 62. In this 
manner all of the sections are obtained, to which laps must be 
allowed for wiring and seaming. 



SHEET-METAL WORK $L 



TABLES. 

Hie following tables will be found convenient for the Sheet-Metal Worker: 

TABLES PAGE. 

Weight of Cast Iron, Wrought Iron, Copper, Lead, Brass and Zinc 62 

Sheet Copper 63 

Sheet Zinc " 64 

Standard Gauge for Sheet Iron and Steel 65 

Weights of Flat Rolled Iron 66-71 

Square and Round Iron Bars 72-73 

Angles and Tees 74 



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SHEET-METAL WORK 



SHEET COPPER. 

Official table adopted by the Association of Copper Manufacturers of 
the United States. Rolled copper has specific gravity of 8.93. One cubic 
foot weighs 558.125 pounds. One square foot, one inch thick, weighs 46.51 
pounds. 



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22 0269 

21 0322 

19 0430 

18 0538 

16 0645 

15 0754 

14 0860 

13.., 095 

12 109 

11. 120 

10 134 

9 148 

8 165 

7 .180 

6 203 

5 220 

4 238 

3 259 

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CO 


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IQ 



SHEET-METAL WORK 



65 



UNITED STATES STANDARD GAUGE FOR SHEET AND PLATE 
IRON AND STEEL 

copy [Public— No. 137] 

An act establishing a standard gauge for sheet and plate iron and steel. 

Be it enacted by the Senate and House of Representatives of the United States of America 
in Congress assembled. That for the purpose of securing uniformity the following is estab- 
lished as the only standard gauge for sheet and plate iron and steel in the United States of 
America, namely: 





THICKNESS 


WEIGHT 




Number of 
Gauge 


Approximate 


Approximate 


Weight per 


Weight per 


Number of 
Gauge 


thickness in 


thickness in 


square foot 


square foot 






fractions of 


decimal parts 


in ounces 


in pounds 






an inch 


of an inch 


avoirdupois 


avoirdupois 




0000000 


1-2 


.5 


320 


20. 


0000000 


000000 


15-32 


.46875 


300 


18.75 


000000 


00000 


7-16 


.4375 


280 


17.5 


00000 


0000 


13-32 


.40625 


260 


16.25 


0000 


000 


3-8 


.375 


240 


15. 


000 


00 


11-82 


.34875 


220 


13.75 


00 





5-16 


.3125 


200 


12.5 





i 


9-32 


.28125 


180 


11.25 


1 


2 


17-64 


.265625 


170 


10.625 


2 


3 


1-4 


.25 


160 


10. 


3 


4 


15-S4 


.234375 


150 


9.375 


4 


5 


7-32 


.21875 


140 


8.75 


5 


6 


13-64 


.203125 


130 


8.125 


6 


7 


3-16 


.1875 


120 


7.5 


7 


8 


11-64 


.171875 


110 


6.875 


8 


9 


5-32 


.15625 


100 


6.25 


9 


10 


9-64 


.140625 


90 


5.625 


10 


11 


1-8 


.125 


80 


5. 


11 


12 


7-64 


.109375 


70 


4.375 


12 


13 


3-82 


.09375 


60 


8.75 


13 


14 


5-64 


.078125 


50 


3.125 


14 


15 


9-128 


.0703125 


45 


2.8125 


15 


16 


1-16 


.0625 


40 


2.5 


16 


17 


9-160 


.05625 


36 


2.25 


17 


18 


1-20 


.05 


32 


2. 


18 


19 


7-160 


.04375 


28 


1.75 


19 


20 


3-80 


.0375 


24 


1.5 


20 


21 


11-320 


.034375 


22 


1.375 


21 


22 


1-32 


.03125 


20 


1.25 


22 


23 


9-320 


.028125 


18 


1.125 


23 


24 


1-40 


.025 


16 


1. 


24 


25 


7-820 


.021875 


14 


.875 


25 


26 


3-160 


.01875 


12 


.75 


26 


27 


11-640 


.0171875 


11 


.6875 


27 


28 


1-64 


.015625 


10 


.625 


28 


29 


9-640 


.0140625 


9 


.5625 


29 


30 


1-80 


.0125 


8 


.5 


30 


81 


7-640 


.0109375 


7 


.4375 


31 


32 


13-1280 


.01015625 


Wz 


.40625 


32 


33 


3-320 


.009375 


6 


.375 


33 


34 


11-1280 


.00859375 


5^ 


.34375 


34 


35 


5-640 


.0078125 


5 


.3125 


35 


36 


9-1280 


.00703125 


4% 


.28125 


36 


S7 


17-2560 


.0066406 


Wx 


.265625 


37 


38 


1-160 


.00625 


4 


.25 


38 



And on and after July first, eighteen hundred and ninety-three, the same and no other 
shall be used in determining duties and taxes levied by the United States of America on sheet 
and plate iron and steel. But this act shall not be construed to increase duties upon any 
articles which may be imported. 

Sec. 2. That the Secretary of the Treasury is authorized and required to prepare suitable 
standards in accordance herewith. 

Sec. 8. That in the practical use and application of the standard gauge hereby estab- 
lished a variation of two and one-half per cent either way may be allowed. 

Approved, March 3, 189?, 



SHEET-METAL WOEK 



WEIGHTS OF PLAT ROLLED IRON PER LINEAR FO€T« 

Iron weighing 480 pounds per cubic foot. 



Thickness 
in Inches. 



X* 



J 

if 

if 

it 

U 

it 



n 



i" ik" 



.208 
.417 
.625 
.833 

1.04 
1.25 
1.46 
1.67 

1.88 
2.08 
2.29 
2.50 

2.71 
2.92 
3.13 
3.33 

3.54 
3.75 
3.96 
4.17 

4.37 
4.58 
4.79 
5.00 

5.21 
5.42 
5.63 
5.83 

6.04 
6.25 
6.46 
6.67 



W'\W" 



260 
.521 
.781 
1.04 

1.30 
1.56 
1.82 
2.08 

2.34 
2.60 
2.86 
3.13 

3.39 
3.65 
3.91 
4.17 

4.43 
4.69 
4.95 5.94 
5.21 6.25 



5.47 
5.73 
5.99 
6.25 

6.51 
6.77 
7.03 
7.29 

7.55 
7.81 
8.07 



.313 
.625 
.938 
1.25 

1.56 
1.88 
2.19 
2.50 

2.81 
3.13 
3.44 
3.75 

4.06 
4.38 
4.69 
5.00 

6.31 
5.63 



6.56 
6.88 
7.19 
7.50 

7.81 
8.13 
8.44 
8.75 

9.06 
9.38 
9.69 
10.00 



.365 
.729 
1.09 
1.46 

1.82 
2.19 
2.55 
2.92 

3.28 
3.65 
4.01 
4.38 

4.74 
5.10 
5.47 



2" 



6.20 
6.56 
6.93 
7.29 



8.02 
8.39 
8.75 

9.11 
9.48 
9.84 
10.21 

10.57 
10.94 
11.30 
11.67 



2K" 



5.83 6.67 



.417 
.833 
1.25 
1.67 

2.08 
2.50 
2.92 
3.33 

3.75 
4.17 
4.58 
5.00 

5.42 
5.83 
6.25 



7.08 
7.50 
7.92 



8.75 

9.17 

9.58 

10.00 

10.42 
10.83 
11.25 
11.67 

12.08 
12.50 
12.92 
13.33 



.469 
.938 
1.41 
1.88 

2.34 
2.81 
3.28 
3.75 

4.22 
4.69 
6.16 



2K" 



5.63 6.25 



6.09 
6.56 
7.03 
7.50 

7.97 
8.44 
8.91 
9.38 

9.84 
10.31 
10.78 
1155 

11.72 
12.19 
12.66 
13.13 

13.59 
14.06 
14.53 
15.00 



I 



.521 
1.04 
1.56 
2.08 

2.60 
3.13 
3.65 
4.17 

4.69 
5.21 
5.73 



2%" 12" 



6.77 
7.29 
7.81 



9.90 
10.42 

10.94 
11.46 
11.98 
12.50 

13.02 
13.54 
14.06 
14.58 

15.10 
15.63 
16.15 
16.67 



.573 
1.15 
1.72 
2.29 

2.86 
3.44 
4.01 
4.58 

5.16 
5.73 
6.30 



7.45 
8.02 
8.59 
9.17 

9.74 
10.31 
10.89 
11.46 

12.03 
12.60 
13.18 
13.75 

14.32 
14.90 
15.47 
16.04 

16.61 
17.19 
17.76 
18.83 



2.50 
5.00 
7.50 
10.00 

12.50 
15.00 
17.50 
20.00 

22.60 
25.00 
27.50 
30.00 

32.50 
35.00 
37.60 
40.0* 

42.50 
45.09 
47.50 
50.00 

52.50 
55.00 
57.50 
60.00 

62.50 
65.00 
67.50 
70.00 

72.50 
75.00 
77.50 



SHEET-METAL WORK 



01 



WEIGHTS OF FLAT ROLLED IRON PER LINEAR FOOT. 

(Continued) 



Thickness 
in Inches, 


i" ■ ■ 

3" 


3K" 


3%" 


W!' 


4" 


w 


w 


4%" 


12" 


t 


.625 


.677 


.729 


.781 


.833 


.885 


.938 


.990 


2.50* 


1.25 


1.35 


1.46 


1.56 


1.67 


1.77 


1.88 


1.98 


5.00 


ft 


1.88 


2.03 


2.19 


2.34 


2.50 


•2.66 


2.81 


2.9? 


^7.60 


i 


2.50 


2.71 


2.92 


3.13 


3.33 


3.54 


3.75 


3.96 


10.00 


■fV 


3.13 


3.39 


3.65 


3.91 


4.17 


4.43 


4.69 


4.95 


12:50 


I 


3.75 


4.06 


4.38 


4.69 


5.00 


5.31 


5.63 


5.94 


15.00 


tV 


4.38 


4.74 


6.10 


5.47 


5.83 


6.20 


6.56 


6.93 


17.50 


¥ 


5.00 


5.42 


5.83 


6.25 


6.67 


7.08 


7.50 


7.92 


20.00 


<& 


5.63 


6.09 


6.56 


7.03 


7.50 


7.97 


8.44 


8.91 


22.50 


$■ 


6.25 


6.77 


7.29 


7.81 


8.33 


8.85 


9.38 


9.90 


25.00 


H 


6.88 


7.45 


8.02 


8.59 


9.17 


9.74 


10.31 


10.89 


27.50 


1 


7.50 


8.13 


8.75 


9.38 


10.00 


10.63 


11.25 


11.88 


30.00 


if 


8.13 


8.80 


9.43 


10.16 


10.83 


11.51 


12.19 


12.86 


32.50 


¥ 


8.75 


9.48 


10.21 


10.94 


11.67 


12.40 


13.13 


13.85 


35.00 


if 


9.38 


10.16 


10.94 


li:72 


12.50 


13.28 


14.06 


14.84 


37.50 


1 


10.00 


10.85 


11.67 


12.50 


13.33 


14.17 


15.00 


15.83 


40.00 


il^r 


10.63 


11.51 


12.40 


13.28 


14.17 


15.05 


15.94 


16.82 


42.50 


it 


11.25 


12.19 


13.13 


14.06 


15.00 


15.94 


16.88 


17.81 


45.00 


if 


11.88 


12.86 


13.85 


14.84 


15.83 


16.82 


17.81 


18.80 


47.50 


12.50 


13.54 


14.58 


15.63 


16.67 


17.71 


18.75 


19.79 


50.00 


1ft 


13.13 


14.22 


15.31 


16.41 


17.50 


18.59 


19.69 


20.78 


52.50 


ll 


13.75 


14.90 


16.04 


17.19 


18.33 


19.48 


20.63 


21.77 


55.00 


14.38 


15.57 


16.77 


17.97 


19.17 


20.36 


21.56 


22.76 


57.50 


1? 


15.00 


16.25 


17.50 


18.75 


20.00 


21.25 


22.50 


23.75 


60.00 


1ft 


15.63 


16.93 


18.23 


19.53 


20.83 


22.14 


23:44 


24.74 


62.50 


1? 


16.25 


17.60 


18.96 


20.31 


21.67 


23.02 


24.38 


25.73 


65.00 


m 


16.88 


18.28 


19.69 


21.09 


22.50 


23.91' 


25.31 


26.72 


67.50 


if- 


17.50 


18.96 


20.42 


21.88 


23.33 


24.79 


26.25 


27.71 


70.00 


1H 


18.13 


19.64 


21.15 


22.66 


24.17 


25.68 


27.19 


28.70 


72.50 


l? 


18.75 


20.31 


21.88 


23.44 


25.00 


26.56 


28.13 


29.69 


75.00 


m 


19.38 i 


20.99 


22.60 


24.22 


25.83 


27.45 


29.06 


30.68 


77.50 


J j 


20.00 


21.67 23.33 


25.00 


26.67 


28.33 


30.00 


31.67 


80,00 


: 


1 


i ' 




i 


1 


1 







SHEET-METAL WORK: 



WEIGHTS OF FLAT ROLLED IRON PER LINEAR FOOT. 

(Continued) 



Thickness 
in Inches. 


5" 


5%" 
1.09 


5%" 


5%" 


6" 


6K" 


6%" 


6%" 
1.41 


12" 


A 


1.04 


1.15 


1.20 


1.25 


1.30 


1.35 


2.50 


¥ 


2.08 


2.19 


2.29 


2.40 


2.50 


2.60 


2.71 


2.81 


6.00 


A 


3.13 


3.28 


3.44 


3.59 


3.75 


3.91 


4.06 


4.22 


7.50 


i 


4.17 


4.38 


4.58 


4.79 


5.00 


5.21 


5.42 


5.63 


10.00 


A 


5.21 


5.47 


5.73 


5.99 


6.25 


6.51 


6.77 


7.03 


12.50 


T 


6.25 


6.56 


6.88 


7.19 


7.50 


7.81 


8.13 


8.44 


15.00 


A 


7.29 


7.66 


8,02 


8.39 


8.75 


9.11 


9.48 


0.84 


17.50 


I 


8.33 


8.75 


9.17 


9.58 


10.00 


10.42 


10.83 


11.25 


20.00 


A 


9.38 


9.84 


10.31 


10.78 


11.25 


11.72 


12.19 


12.66 


22.5ft 


¥ 


10.42 


10.94 


11.46 


11.98 


12.50 


13.02 


13.54 


14.06 


25.00 


A 


11.46 


12.03 


12.60 


13.18 


13.75 


14.32 


14.90 


15.47 


27.50 


i 


12.50 


13.13 


13.75 


14.38 


15,00 


15.63 


16.25 


16.88 


30.00 


if 


13.54 


14.22 


14.90 


15.57 


16.25 


16.93 


17.60 


18.28 


32.50 


F ' 


14.58 


15.31 


16.04 


16.77 


17.50 


18.23 


18.96 


19.69 


35.00 


it 


15.63 


16.41 


17.19 


17.97 


18.75 
2O.0O 


19.53 


20.31 


21.09 


37.50 


1 


16.67 


17.50 


18.33 


19.17 


20.83 


21.67 


22.50 


40.00 


*A 


lWl 


18.59 


19.48 


20.36 


2lJ5 


22.14 


23.02 


23.91 


42.50 


n 


18.75 


19.69 


20.63" 


21.56 


22.5;0 


23.44 


24.38 


25.31 


45.00 


1A 


19.79 


20.78 


21.77 


22.76 


23.75 


24.74 


25.73 


26.72 


47.50 


■n 


20.83 


21.88 


22.92 


23.96 


25.00 


26.04 


27.08 


28.13 


50.00 


1A 


21.88 


22.97 


24.06 


25.18 


26.25 


27.34 


28.44 


29.53 


52.50 


H 


22.92 


24.06 


25.21 


26.35 


27.50 


28.65 


29.79 


30.94 


55.00 


1A' 


23.96 


25.16 


26.35 


27.55 


28.75 


29.95 


31.15 


32.34 


57.50 


H 


25.00 


26.25 


27.50 


28.75 


30.00 


31.25 


32.50 


33.75 


60.00 


1A 


26.04 


27.34 


28.65 


29.95 


31.25 


32.55 


33.85 


35.16 


62.50 


U 


27.08 


28.44 


29.79 


31.15 


32.50 


33.85 


35.21 


36.56 


65.00 


1H 


28.13 


29.53 


30.94 


32.34 


33.75 


•35.16 


36.56 


37.97 


67.50 


i| 


29.17 


30.63 


32.08 


33.54 


35.00 


36.46 


37.92 


39.38 


70.00 


U* 


30.21 


31.72 


33.23 ' 34.74 


36.25 


37.76 


39.27 


40.78 


72.50 


if 


31.25 


32.81 


34.38 35.94 


37.50 


39.06 


40.63 


42.19 


75.00 


i*t 


32.29 


33.91 


85.52 


37.14 


38.75 


'40.36 


41.98 


43.59 


77.50 


8 


33.33 


35.00 


36.67 


38,33 


40.00 


41.67 


43.33 


45.00 


80.00 






1 


. 


> 




, 









SHEET-METAL WORK 



WEIGHTS OF FLAT ROLLED IRON PER LINEAR FOOT. 

(Continued) 



tbidbuss* 
inInohftL- 


7" 


7H" 


7&" 


IK" 


8" 


QH" 


B%" 


&X" 


J2-' 


A 


1.46 


1.51 


1.56 


1.61 


1.67 


1.72 


1.77 


1.82 


2.50 


A 


2.92 


8.02 


3.13 


853 


8.33 


8.44 


8.54 


3.65 


6.00 


4.38 


4.53 


4.69 


4.84 


5.00 


5.16 


5.31 


5.47 


7.50 


? 


5.83 


6.04 


6.25 


6.46 


6.67 


6.88 


7.08 


759 


10.00 


A 


7.29 


7.55 


7.81 


8.07 


8.83 


8.59 


8.85 


9.11 


12.50 


A 


8.75 


9.06 


9.38 


9.69 


10.00 


10.31 


10.63 


10.94 


15.00 


10.21 


10.57 


10.94 


11.30 


11.67 


12.03 


12.40 


12.76 


17.50 


T 


11.67 


12.08 


12.50 


12.92 


13.33 


13.75 


14.17 


14.58 


20.00 


A 


13.13 


13.59 


14.06 


14.53 


15.00 


15.47 


15.94 


16.41 


'22.50 


£ 


14.58 


15.10 


15.63 


16.15 


16.67 


17.19 


17.71 


18.23 


25.00 


16.04 


16.61 


17.19 


17.76 


18.33 


18.91 


19.48 


20.05 


27.50 


¥ 


17.50 


18.13 


18.75 


.19.38 


20.00 


20.63 


2155 


21.88 


30.00 


H- 


18.96 


19.64 


20.31 


20.99 


21.67 


22.34 


23.02 


23.70 


32.50 


1 


20.42 


21.15 


21.88 


22.60 


23.33 


24.06 


24.79 


25.52 


35.00 


A 


21.88 


22.66 


23.44 


24.22 


25.00 


25.78 


26.56 


27.34 


37.50 


1 


23.83 


24.17 


25.00 


25.83 


26.67 


27.50 


28.33 


29.17 


40.00 


*A 


24.79 


25.68 


26.56 


27.45 


28.33 


29.22 


30.10 


30.99 


42.50 


i* 


26.25 


27.19 


28.13 


29.06 


30.00 


30.94 


31.88 


32.81 


45.00 


1A 


27.71 


28.70 


29.69 


30.68 


31.67 


32.66 


33.65 


34.64 


47.50 


n. 


29.17 


30.21 


31.25 


32.29 


83.38 


34.88 


35.42 


36.46 


50.00 


1A 


80.62 


31.72 


32:81 


83.91 


85.00 


36.09 


37.19 


3858 


62.50 


If 


32.08 


33.23 


34.38 


35.52 


86.67 


37.81 


38.96 


40.10 


65.00 


1A 


33.54 


34.74 


35.94 


37.14 


38.33 


39.53 


40.73 


41.93 


57.50 


H 


35.00 


36.25 


37.50 


38.75 


40.00 


41.25 


42.50 


43.75 


60.00 


1A 


36.46 


37.76 


39.06 


40.36 


41.67 


42.97 


44.27 


45.57 


62.50 


if 


37.92 


39.27 


40.63 


41.98 


43.33 


44.69 


46.04 


47.40 


65.00 


m 


'39.38 


40.78 


42.19 


43.59 


45.00 


46.41 


47.81 


4952 


67.50 


it 


40.83 


42.29 


43.75 


45.21 


46.67 


48.13 


49.58 


51.04 


70.00 


1H 


42.29 


43.80 


45.31 


46.82 


48.33 


49.84 


51.35 


52.88 


72.50 


1? 


43.75 


45.31 


46.88 


48.44 


50.00 


51.56 


53.13 


54.69 


75.00 


1H 


45.21 


46.82 


48.44 


50.05 


51.67 


53.28 


54.90 


56.51 


77.50 


2 


46.67 


48.33 


50.00 


51.67 


53.33 


55.00 


56.67 


58.33 


80.00 



7© 



SHEET-METAL WORK 



WEIGHTS OP FLAT ROLLED IRON PER LINEAR FOOT- 

(Continued) 



Thickness 
in Inohes. 


9" 


w 

1.93 
3.85 

5.78 
7.71 


W 


W 


10" 

2.08 
4.17 
6.25 
8.33 


1(H" 


10£" 


lOf" 

2.24 
4.48 
6.72 
8.96 


12" 


* 

f 


1.88 
3.75 
5.63 
7.50 


1.98 
3.96 
5.94 
7.92 


2.03 
4.06 
6.09 
8.13 


2.14 
4.27 
6.41 
8.54 


2.19 

4.38 
6.56 
8.75 


2.50 
5.00 
7.50 
10.00 


1 


9.38 
11.25 
13.13 
15.00 


9.64 
11.56 
13.49 
15.42 


9.90 

11.88 
13.85 
15.83 


10.16 
12.19 
14.22 
16.25 


10.42 
12.50 
14.58 
16.67 


10.68 
12.81 
14.95 
17.08 


10.94 
13.13 
15.31 
17.50 


11.20 
13.44 
15.68 
17.92 


12.50 
15.00 
17.50 
20.00 


.1 
ii 
1 


16.88 
18.75 
20.63 
22.50 


17.34 
19.27 
21.20 
23.13 


17.81 
19.79 
21.77 
23.75 


18.28 
20.31 
22.34 
24.38 


18.75 
20.83 
22.92 
25.00 


19.22 
21.35 
23.49 

25.62 


19.69 
21.88 
24.06 
26.25 


20.16 
22.40 
24.64 
26.88 


22.50 
25.00 
27.50 
30.00 


t 


24.38 
26.25 
28.13 
30.00 


25.05 
26.98 
28.91 
30.83 


25.73 
27.71 
29.69 
31.67 


26.41 
28.44 
30.47 
32.50 


27.08 
29.17 
31.25 
33.33 


27.76 
29.90 
32.03 
34.17 


28.44 
30.63 
32.81 
35.00 


29.11 
31.35 
33.59 
35.83 


32.50 
35.00 
37.50 
40.00 


It 

J* 
ti 


31.88 
33.75 
35.63 
37.50 


32.76 
34.69 
36.61 
38.54 


33.65 
35.63 
37.60 
39.58 


34.53 
36.56 
38.59 
40.63 


35.42 
37.50 
39.58 
41.67 


36.30 
38.44 
40.57 
42.71 


37.19 
39.38 
41.56 
43.75 


38.07 
40.31 
42.55 
44.79 


42.50 
45.00 
47.50 
50.00 


it 

it 


39.38 
41.25 
43.13 
45.00 


40.47 
42.40 
44.32 
46.25 


41.56 
43.54 
45.52 
47.50 


42.66 
44.69 
46.72 
48.75 


43.75 
45.83 
47.92 
50.00 


44.84 
46.98 
49.11 
51.25 


45.94 
48.13 
50.31 
52.50 


47.03 
49.27 
51.51 
53.75 


52.50 
55.00 
57.50 
60.00 


1 $ 

1 & 

14 


46.88 
48.75 
50.63 
52.50 


48.18 
50.10 
52.03 
53.96 


49.48 
51.46 
53.44 
55.42 


50.78 
52.81 
54.84 
56.88 


52.08 
54.17 
56.25 
58.33 


53.39 
55.52 
57.66 
59.79 


54.69 
56.88 
59.06 
61.25 


55.99 
58.23 
60.47 
62.71 


62.50 
65.00 
67.50 
70.00 




54.38 
56.25 
58.13 
60.00 


55.89 
57.81 
59.74 
61.67 


57.40 
59.38 
61.35 
63.33 


58.91 
60.94 
62.97 
65.00 


60.42 
62.50 
64.58 
66.67 


61.93 
64.06 
66.20 
68.33 


63.44 
65.63 
67.81 
70.00 


64.95 
67.19 
69.43 
71.67 


72.50 
75.00 
77.50 
80.00 


1 










i 











SHEET-METAL WORK 



ft 



\ 

WEIOHTS OP FLAT ROLLED IRON PER LINEAR FOOT. 

(Concluded) 



Thickness 
in Inches. 



t 
t 



* 



It 

it 

*! 

it 
it 






ii' 



2.29 
4.58 
6.88 
9.17 

11.46 
13.75 
16.04 
18.33 

20.63 
22.92 
25.21 
27.50 

29.79 
32.08 
34.38 
36.67 

38.96 
41.25 
43.54 
45.83 

48.13 
50.42 
52.71 
55.00 

57.29 
59.58 
61.88 
64.17 

66.46 
68.75 
71.04 
73.33 



11|" 



2.34 
4.69 
7.03 



11.72 
14.06 
16.41 
18.75 

21.09 
23.44 
25.78 
28.13 

30.47 
32.81 
35.16 
37.50 



11J" 11|" 12" 



2.40 
4.79 
7.19 
9.58 

11.98 
14.88 
16.77 
19.17 

21.56 
23.96 
26.35 
28.75 

31.15 
33.54 
35.94 



39.84 40.73 
42.19 43.13 



44.53 
46.88 

4952 
51.56 
53.91 
56.25 

58.59 
60.94 
63.28 
65.63 

67.97 
70.31 
72.66 
75.00 



45.52 
47.92 

50.31 
52.71 
55.10 
57.50 

59.90 
62.29 
64.69 
67.08 

69.48 
71.88 
74.27 
76.67 



2.45 
4.90 
7.34 
9.79 

12.24 
14.69 
17.14 
19.58 

22.03 

24.48 
26.93 
29.38 

31.82 
34.27 
36.72 
39.17 

41.61 
44.06 
46.51 
48.96 

51.41 
53.85 
56.30 
58.75 

61.20 
63.65 
66.09 
68.54 

70.99 
73.44 
75.89 
78.33 



2.50 

5.00 

7.50 

10.00 

12.50 
15.00 
17.50 
20.00 

22.50 
25.00 
27.50 
30.00 

32.50 
35.00 
37.50 
40.00 

42.50 
45.00 
47.50 
50.00 

52.50 
55.00 
57.50 
60.00 

62.50 
65.00 
67.50 
70.00 

72.50 
75.00 
77.50 
80.00 



12|" 



12£" 



2.55 

5.10 

7.66 

10.21 

12.76 
15.31 
17.86 
20.42 

22.97 
25.52 
28.07 
30.63 

33.18 
35.73 
38.28 
40.83 

43.39 
45.94 
48.49 
51.04 

53.59 
56.15 
58.70 
6155 

63.80 
66.35 
68.91 
71.46 

74.01 
76.56 
79.11 
81.67 



2.60 

5.21 

7.81 

10.42 

13.02 
15.63 
18.23 
20.83 

23.44 
26.04 
28.65 
31.25 

33.85 
36.46 
39.06 
41.67 

44.27 
46.88 
49.48 
52.08 

54.69 
57.29 
59.90 
62.50 

65.10 
'67.71 
70.31 
72.92 

75.52 
78.13 
80.73 

83,33 



2.66 
5.31 
7.97 
10.63 

13.28 
15.94 
18.59 
21.25 

23.91 
26.56 
29.22 
31.88 

34.53 
37.19 
39.84 
42.50 

45.16 
47.81 
50.47 
53.13 

55.78 
58.44 
61.09 
63.75 

66.41 
69.06 
71.72 
74.38 

77.03 

79.69 
82.34 
85.00 



m as J 

9£J§ 
O-ttR 



£ 



IS 



SHEET-METAL WORK 



SQUARE AND ROUND IRON BARS. 



TMokness 
or Diameter 
in Incites. 


Weight of 
One Foot long. 


"Weight of 

O Bar 

One foot long. 


Area of 
j*~| Bar 

in sq. inches. 


Area of 
O Bar 

in sq. inches. 


Circumference 
of O Bar 
in inches. 




t 
A 


.013 
.052 
.117 


.010 
.041 
.092 


.0039 
.0156 
.0352 


.0031 
.0123 
.0276 


.1983 
.3927 
.5890 


i 


.208 
.320 
.469 
.638 


.164 
.256 
.368 
.501 


.0625 
.0977 
.1406 
.1914 


.0491 
.0767 
.1104 
.1503 


.7854 

.9817 

1.1781 

1.3744 


1 

t 

•H 


.833 
1.055 
1.302 
1.576 


.654 

.828 

1.023 

1.237 


.2500 
.3164 
.3908 

.4727 


.1963 

.2485 
.3068 
.3712 


1.5708 
1.7671 
1.9635 
2.1598 


? 

1 s 

Iff 


1.875 
2.201 
2.552 
2.930 


1.473 
1.728 
2.004 
2.301 


.5625 
.6602 
.7656 

.8789 


.4418 
.5185 
.6013 
.6903 


2.3562 
2.6525 
2.7489 
2.9452 


1 

i 


3.333 
3.763 
4.219 
4.701 


2.618 
2.955 
3.313 
3.692 


1.0000 
1.1289 
1.2656 
1.4102 


.7854 

.8866 

.9940 

1.1075 


3.1416 
3.3379 
3.5343 
3.7306 


1 

i 


5.208 
5.742 
6.302 
6.888 


4.091 
4.510 
4.950 
5.410 


1.5625 
1.7227 
1.8906 
2.0664 


1.2272 
1.3530 
1.4849 
1.6230 


3.9270 
4.1233 
4.3197 
4.5160 




7.500 
8.138 
8.802 
9.492 


5.890 
6.392 
6.913 
7.455 


2.2500 
2.4414 
2.6406 

2.8477 


1.7671 
1.9175 
2.0739 
2.2365 


4.7124 
4.9087 
5.1051 
5.3014 




10.21 
10.95 
11.72 
12.51 


8.018 
8.601 
9.204 
9.828 


3.0625 
3.2852 
3.5156 
3.7539 


2.4053 
2.5802 
2.7612 
2.9483 


5.4978 
5.6941 
5.8905 
0.0868 


2 

t 

A 


13.33 
14.18 
15.05 
15.95 


10.47 
11.14 
11.82 
12.53 


4.0000 
4.2539 
4.5156 
4.7852 


3.1416 
3.3410 
3.6466 
3.7583 


6.2832 
6.4795 
6.6759 
6.8722 


i 


16.88 
17.83 
18.80 
19.80 


13.25 
14.00 
14.77 
15.55 


5.0625 
5.3477 
5.6406 
5.9414 


3.9761 
4.2000 
4.4301 
4.6664 


7.0680 
7.2649 
7.4613 
7.6578 


i 


20.83 
21.89 
22.97 
24.08 


16.36 
17.19 
18.04 
18.91 


8.2500 
6.5664 
6.8906 
7.2227 


4.9087 
5,1572 
5.4119 
5.6727 1 


7.8540 
8.0503 
8.2467 
8.4430 



bHEET-METAL WGBK 



SQUARE AND ROUND IRON BARS. 

(Concluded) 



Thickness 

«r Diameter 

in Inches. 


Weight of 
□ Biff- 
One Foot long. 


Weight of 

O Bar 

One Foot long. 


Area of 

□ Bar 

in sq. inches. 


Area of 
O Bar 

in sq. inches. 


Circumferencs 
of O Bar 
in inches. 




25.21 
26.87 
27.55 
28.76 


19.80 
20.71 
21.64 
22.59 


7.5625 
7.9102 
8.2656 
8.6289 


5.9396 
6.2126 
6.4918 
6.7771 


8.6394 
8.8357 
9.0321 
9.2284 


d 

t 


30.00 
31.26 
32.55 
33.87 


23.56 
24.55 
25.57 
26.60 


9.0000 
9.3789 
9.7656 
10.160 


7.0686 
7.3662 
7.6699 
7.9798 


9.4248 
9.6211 
9.8175 
10.014 


t 


35.21 
36.58 
37.97 
39.39 


27.65 
28.73 
29.82 
30.94 


10.563 
10.973 
11.391 
11.816 


8.2958 
8.6179 
8.9462 
9.2806 


10.210 
10.407 
10.603 
10.799 


i 


40.83 
42.30 
43.80 

45.33 

• 


32.07 
33.23 
34.40 
35.60 


12.250 
12.691 
13.141 
13.598 


9.6211 
9.9678 
10.321 
10.680 


10.99© 
11.192 
11.388 
11.585 


1 


46.88 
48.45 
50.05 
61.68 


36.82 
38.05 
39.31 
40.59 


14.063 
14.535 
15.016 
15.504 


11.045 
11.416 
11.793 
12.177 


11.781 
11.977 
12.174 
.12.370 


4 

f 
ft 


53.33 
55.01 
56.72 
58.45 


41.89 
43.21 
44.55 
45.91 


16.000 
16.504 
17.016 
17.535 


12.566 
12.962 
13.364 
13.772 


12.566 
12.763 
12.959 
13.155 




60.21 
61.99 
63.80 
65.64 


47.29 
48.69 
50.11 
51.55 


18.063 
18.598 
19.141 
19.691 


14.186 
14.607 
15.033 
15.466 


13.352 
13.548 
13.744 
13.941 




67.50 
69.39 
71.30 
73.24 


53.01 
54.50 
56.00 
57.52 


20.250 
20.816 
21.391 
21.973 


15.904 
16.349 
16.800 
17.257 


14.137 
14.334 
14530 
14.726 


I 


75.21 
77.20 
79.22 
81.26 


69.07 
60.63 
62.22 
63.82 


22.563 
23.160 
23.766 
24.379 


17.721 
18.190 
18.665 
19.147 


14.923 
15.119 
15.315 
15.512 


„ 6 


83.33 


65.45 


25.000 


19.635 


15.708 



ANGLE IRON. 

Weight Per Linear Foot. 



• x« %% 24 Lbs. 

• x6 xft 16& - 

4 x4 %H 12^ • 

*H**%*& 9 - 

8 x3 x% 7 - 

2&x2Kx& 5 - 

«tf*2&*& m m 



2 x2 sK 3KLb* 

Wsl^xA 2% « 

l&slKsA 2 « 

1&s1Kxt% 1M " 

1 xl %U 1 « 

%s %x« K " 



& 


z8 


*% 


I 


xfl 


*% 


8 


x3 


*K 


4 


x4 


*K 



TEE IRON. 
Weight Per Linear Foot. 



30 Lbs. 

30 • 

...16M - 

14 ■ 

B^xS^xK 12K " 

3 x3 x% 1% " 

2>^x2^xK 8 - 

2*x2Kx& 5 - 



mx2K*K 4 t*» 

2 x2 xK 8# " 

\%x\%x\i 8 * 

iHxiKxK *% " 

iKxVAxH 2H u 

1 xl xH 1 • 

%* %*K H * 



CONSTRUCTION DRAWING, 

SHowma 

•SHEET i^ETAL DRUM AND VENTILATOR IN 

VETiTIUATIOri WOPJi 



^Rivet 




Joint 
between Vent 
&.nd. Drum . 



ATtic rioor> 



Sectioned view/ showing ventUsJtion 

pipes cormecied Xo drum in eJtic 

edso sfea-rn coils in drum Xo 

create suction. 



— 



SHEET METAL WORK. 



PART II. 



ELEVATION 



PROBLEHS FOR LIGHT GAUGE HETAL. 

It is often the case that the sheet 
metal worker receives plans for 
vent, heat, or blower pipes to be 
constructed, in which the true 
lengths and angles are not shown 
but must be obtained from the 
plans or measurements at the 
building. 

Figs. 65 and 66 show the prin- 
ciples employed for obtaining the 
true angles and lengths in oblique 
piping, it being immaterial whether 
the piping is round, square, or oval 
in section. The only safe way in 
obtaining these angles is to use the 
center line as a basis and after this 
line has been obtained, build the 
pipe around it, so to speak. In Fig. 
65 let A B C represent the eleva- 
tion of the elbow shown in plan by 
D E. Through the center of the 
pipes draw the center line abed 
which intersect the center lines of 
the pipe in plan at e and/*. In ele- 
vation the rise of the middle piece 
B on the center line is equal to h c 
and projects to the right a distance 
equal to b h, shown in plan by ef\ 
this same pipe projects forward ia. 
While the miter lines in elevation ij 




Fig. 65. 
plan a distance equal to e a. 



76 



SHEET METAL WORK 



and k I have been drawn straight, they would in reality show curved 
lines; those lines have not been projected as there is no necessity 
for doing so. 

"With the various heights and projections in plan and eleva- 
tion the true length and true angles are obtained as shown in Fig. 




Fig. 66. 

66, in which draw the horizontal line e f equal to <s/'in plan in 
Fig. 65. Take the height from h to c and place it from /"to c in 
Fig. 66 on a vertical line erected from f. Draw a line from e to 
c which is the true length on the center line of the pipe shown by 
B in elevation in Fig. 65. From the points e and e in Fig. 66 
draw perpendicular lines, making Y e X and X c Z = the true angles 
shown by a b X and X g d respectively in Fig. 65. On either 
side of the center line in Fig. 66 lay off the half diameter of the 
pipe as shown, and in its proper position draw the profile W. 



SHEET METAL WORK 



77' 



Divide this into equal spaces and obtain the pattern A B D E C 
in the usual manner. As both angles are similar the miter cut 
CED can be used for all of the patterns. In drawing this prob- 
lem for practice make the diameter of the pipe 2 inches, the height 
from h to c 3| inches in Fig. 65, the projection b to h 3£ inches, 
and the projection in plan e to a 5^ inches. 

Our next problem is that of a rain-water cut-off, a perspective 
view of which is shown in Fig. 67. While the miter cuts in this prob- 
lem are similar to elbow work the intersection between the two 
beveled arms, and the cut-off or slide on the inside require atten- 
tion. Make the diameter of the 
three openings each 2 inches; A 
to B (Fig. 68) li| inches. From 
B at an angle of 45° draw B C3| 
inches and CD2 inches. From 
G draw the vertical miter line 
G h. Make the distance from B 
to T -| inch. Place the line d e 
of the cut-off J inch above the 
line T U as indicated at a and 
the line e c to the right of h G, as 
indicated by h, a distance of T 3 j- 
inch. Parallel to G H draw c d ^ig. 67. 

giving slight play room between 

G H, intersecting e d and e c at d and c respectively. From e at right 
angles to d c, draw a line as shown, intersecting h G at f, which is 
the pivot on which the cut-off c d e will turn either right or left. 
The angles of the pipes on opposite sides are constructed in similar 
manner; ABCDEFGHIJKLM will be the elevation, N, 
the section on A M and OPRS the section on I J. B T U L 
shows how far the upper tube projects into the body under which 
the scoop e d e turns right and left to throw the rain water into 
either elbow as desired. The pattern for the upper piece A T U M 
is a straight piece of metal whose circumference is equal to N. 

For the pattern for (A), divide the half section OPE, into 
equal spaces as shown, from which erect lines intersecting the miter 
line H K as shown, and from which, parallel to K L and E G, draw 
lines intersecting the joint lines G h L as shown. As none of tht 




78 



SHEET METAL WORK 



lines just drawn intersect the corner h, it will be necessary to ob- 
tain this point on the half section OPE, from which the stretch- 
out of the pattern is taken. Therefore from h, parallel to L K 
draw h h' intersecting II K at //', from which, parallel to K J, drop 
a line intersecting the profile O P R S at h". At right angles to 
L K draw stretchout of O P R S as shown by similar numbers on 
T 1 U 1 , through which at right angles to T 1 U 1 draw lines which are 
intersected by lines drawn at right angles to L K from similar in- 




Fig. 66. 

tersections on G h L and H K. A line traced through points thus 
obtained as shown by X Y Z V W will be the pattern for (A). 
From f in the elevation at right angles to L K project a line inter- 
secting the miter cut X Y Z at f and/"". At/" andy" holes are 
to be punched in which the pivot f of the scoop c\d e in elevation 
will turn. 

"While the pattern for (B) can be obtained as that for (A) was 
obtained, a short method is to take the distance K to J and place 



SHEET METAL WORK 



79 



it as shown from "W to J 1 and Y to J 2 on the lines of the pattern 
X W and Z V respectively extended. W Y J 2 J 1 will be the pat- 
tern for B. 

To avoid a confusion of lines in the development of the scoop 
or cut-off c d e, this has been shown in Fig. 69 in which d e c is a 
reproduction of d e c in Fig. 68. A true section of the scoop must 
now be drawn on x e in Fig. 69 so that its dimensions will allow 
it to turn easily inside of the joint line G h in elevation in Fig. 
68. Therefore draw any horizontal line as 4 5 in Fig. 69, at right 
angles to which from/" draw a vertical line intersecting 4 5 at f. 
.Now take a distance T ^ inch less 
than one -half the diameter of O R 
in Fig. 68, and place it in Fig. 69 
on either side of the line 4 5 on the 
vertical line just drawn as shown 
from /to 2 and / to 2'. Extend 
d c till it intersects 4 5 at 4. Draw a 
line from 4 to 2'; by bisecting this 
line we obtain the line a b intersect- 
ing 4 5 at i. Then with i as center 
and^ 2' as radius, describe the arc 2' 2. 
From 2 and 2' draw horizontal lines equal to f e as shown by 2 1 
and 2' 1'. Then will 1 4 1' be the true section on x e. Divide 
the half section into equal spaces as shown from 1 to 4, from which 
erect lines intersecting c e and e d. Extend «eas xj, upon which 
place the stretchout of 1 4 1' as shown by similar numbers on xj, 
through which draw vertical lines. These lines intersect with hori- 
zontal lines drawn from similar intersections on d e c. Through 
points thus obtained draw the line 1 n V m which is the desired 
pattern. As the pivot hole f falls directly on line 2, then f'"f" 
will be the position of the holes in the pattern. Laps must be 
allowed to all patterns. 

In putting up rectangular hot air pipe it is often the case 
that the pipe will be placed in the partition of one story, then has 
to fall forward and twist one quarter way around to enter the* par- 
tition of the upper story which runs at right angles to the lower 
one. A perspective view showing this condition is shown in Fig. 
70, where the upper opening turns one quarter on the lower on© 




Fie. 69. 



so 



SHEET METAL WORK 



and leaning to the right as much as is shown in Fig. 71 in plan. 
This problem is known as a transition piece in a rectangular pipe. 
Full size measurements are given in Fig. 71 which should be 
drawn one-half size. The height of the transition piece is 1 foot 
8 inches, the size of the openings, each 4x10 inches turned as 
shown, two inches to the left and two inches above the lower section 
as shown. From the plan construct the front and side elevations as 
shown by the dotted lines. ABCD and EFGH will then be 
the front and side elevations of the transition piece respectively 

FRONT ELEVATION 
S 





PLAN 



Fig. 70. 



Fig. 71. 



equal to 20 inches or 10 inches for practice. Number each side 
of the plan (a), (6), (<?), and (d). Through the front and side 
elevations draw the vertical and horizontal lines S T and U V 
respectively at pleasure. These lines are only used as bases for 
measurements in determining the patterns. For the pattern for 
the side marked (a) in plan take the length of B C and place it 
on the vertical line B C in Fig. 72. Through the points B and 
C draw the horizontal lines E F and H G, making B F and B E, 
and C G and C H equal respectively to the distances measured from 
the line U V in Fig. 71 to points F, E, G, H. Draw lines from 
E to ft and F to G in Fig. 72, which is the pattern for (a). 



SHEET METAL WORK 



SI 



For the pattern for (b) in Fig. 71 take the distance of A D, 
and place it as shown by A D in Fig. 72; through A and D draw 
E F and H G, making A F and A E, and D G and D H equal 




respectively to the distances measured from the line U V in side 
elevation in Fig. 71 to points F, E, G, H. Draw lines from E 
to H and F to G in Fig. 72, which will be the pattern for (b). In 
similar manner obtain the patterns for (c) and (d) in plan in Fig. 71. 
The lengths of E H and F G are placed as shown by similar letters 





Fig. 73. 



Fig. 1L 



in Fig. 72, while the projections to A, B, C, D are obtained 
from A, B, C, D in front elevation in Fig. 71, measuring in 
each instance from S T. 

If desired the top and lower flange shown in the perspective 
in Fig, 70 can be added to the patterns in Fig. 72. Laps are 
allowed to the patterns to allow for double seaming at corners, if, 
however, the pattern should be required in one piece, it would only 



82 



SHEET METAL WORK 



be necessary to join the various pieces in their proper positions as 
shown by a d b c in Fig. 73, which would bring the seam on the 

line J K" in plan in Fig. 71. 
In Fig. 74 is shown a per- 
spective view of a curved 
rectangular chute the con- 
struction of which arises in 
piping and blower work. The 
problem as here presented 
shows the sides a and a in 
vertical planes having the 
same height, while the bot- 
tom b has more width than 
the top c. The top opening 
is to rise above the bottom 
opening a given distance 
equal to C. First draw the 
plan and elevation as shown 
in Fig. 75, make A B equal to 
2 inches, B 8 2^ inches; with 
a radius equal to -| inch, with 
a as center draw the quarter 
circle 8 2. From 2 draw the 
vertical line 2 C equal to 1| 
inches and draw C D equal to 
1^ inches. Make D 1 equal 
to C 2 and using a as center 
and a 1 as radius draw the 
arc 1 b. From A draw a 
line tangent to 1 b as A 7. 
A B C D will be the plan of 
the chute. In line with A B 
draw the section S T U V. 
In line with D C draw the 
section EFIH as shown. 
Place the desired rise of the 
chute as shown by F i in ele- 
vation and from i draw a horizontal line as i K, which intersect hi 




SHEET METAL WORK 



83 



a line drawn from A B in plan as shown. Make K J equal to F E 
and draw the lines F K, K I, and E J, J H. F E J K is the eleva- 
tion of the outside curve, HIK J the inside curve, FIK the 
bottom, and EHJ the top. 

Having the plan and elevation in position we will first draw 
the pattern for the two vertical sides. For the pattern for the side 
of the chute shown by B C in plan proceed as follows: Divide 
the inner curve 2 to 8 into equal parts as shown by 2-4-6 and 8, 
from which points drop lines intersecting the inside of the chute in 
planHJKIas shown. At right angles to J K draw LM, upon which 
place the stretchout of B C in plan as shown by similar letters and 
numbers on L M, through which draw vertical lines which inter- 
sect lines drawn parallel to L M from H J. Through points thus 
obtained draw the line It 2 V 4 V 6 V 8 V N. The same method can 



~~i. — f....... 



^*> 



2 3 4 5 6 7 6 

Fig. 76. 

be employed for the curve P O, but as the height H I and J K are 
equal, having a common profile B C, take the height of H I or J K 
and place it on vertical lines as KP and N O and trace the curve 
E ISf as shown by P O. JS O P R is the pattern for C B in plan; 
To obtain the pattern for the outside curve divide the curve 1-7 
into equal parts as shown, from which drop vertical lines inter- 
secting similar points in E J K F, in elevation at right angles to 
I] F draw W X, upon which place the stretchout of D A in plan as 
shown. From the divisions on W X drop vertical lines, which 
intersect by lines drawn from similar numbered intersections on 
E J. Trace a line through these points as shown by c/'and draw 
d e as explained in connection with the inside pattern, c d ef is 
the pattern for the outside of the chute shown in plan by D A. 

As both the top and bottom of the chute have the same bevel, 
the pattern for one will answer for the other. Connect opposite 
points in plan as shown from C to 1 to 2 to 3 up to 8, then to A. 
In similar manner connect similar points on the bottom in eleva- 
tion as shown from 1 to 2 up to K. The lines in plan represent 



M 



SHEET METAL WORK 



the bases of the sections whose altitudes are equal to the various 
heights in elevation, measured from i K. Take the various lengths 
from 2 to 3 to 4 to 5 to 6 to 7 to 8 to A in plan and place them as shown 
by similar numbers on the horizontal line a h (Fig. 76) ; through 
a b draw vertical lines, equal in height to similar numbers in ele- 
vation, in Fig. 75, measured from the line i K. For example take 
the distance 4 5 in plan and place it as shown by 4 5 in Fig. 76. 
Erect perpendiculars 4 4' and 5 5' equal to 4" 4 and 5" 5 in eleva- 
tion in Fig. 75. Draw a line from 4' to 5' in Fig. 76, which is the 
true length of 4 5 in plan in Fig. 75. Proceed in similar manner 
for the balance of the sections. Take a tracing of 1 2 C D in plan 
and place it as shown by 1, 2, C, D in Fig. 77. Now using 1 as 




- 12 PATTERN FOR 
TOP OR BOTTOM 
A-B-C-D IN FIG.75 



=-J 




Pig. 77. 



Fig. 78. 



center and l v 3 V in (x), in Fig. 75, as radius, describe the arc at 
3, in Fig. 77, which is intersected by an arc, struck from 2 as 
center, and 2' 3', in Fig. 76, as radius. Now with radius equal to 
2 V 4 V in (Y) in Fig. 75 and 2 in Fig. 77 as center, describe the 
arc at 4 which is intersected by an arc, struck from 3 as center and 
3' 4', Fig. 76, as radius. Proceed in this manner, using alternately 
as radius, first the divisions in the pattern (X), Fig. 75, then the 
slant lines in Fig. 76, the divisions in the pattern (Y), Fig. 75, 
then again the lines in Fig. 76 until the line 7 8, Fig. 77, has been 
obtained. Then using 7 as center, with a line equal to T*f in (X), 
Fig. 75, as radius, describe the arc A, Fig. 77, which is inter- 
sected by an arc struck from 8 as center and 8' A, Fig. 76, 
as radius. Then with radius, equal to 8 V N in (Y), Fig. 75, and 
8, Fig. 77, as center, describe the arc B, which is intersected 
by an arc, struck from A as center and A B in plan in Fig. 75 
as radius. Trace lines through points thus obtained in Fig. 77, 



SHEET METAL WORK 



85 



and ABCD will be the desired pattern. Laps must be allowed 
on all patterns for double seaming the corners. 

In Fig. 78 is shown a perspective view of a hopper register 
box usually made from bright tin or galvanized iron in hot air 
piping. In drawing this problem, the student should first draw 
the half plan, making the semi- 



circle 3£ inches diameter, 



and 




placing it directly in the center 
of the rectangular top, which 
is 3| inches wide and 5£ inches 
long. Draw the elevation from 
the plan as shown by A B C D 
E F 6 B, making the vertical 
height Y W, 2^ inches, and the 
flanges at the top and bottom 
each ^ inch. I K L M in plan 
is the horizontal section on A B 
in elevation and OPE the sec- 
tion on E F. 

The pattern will be devel- 
oped by triangulation, and the 
first step is to develop a set of triangles. Divide the quarter circle 
O R into equal spaces, as shown by the numbers 1 to 7 in plan, from 
which draw lines to the apex M. These lines represent the bases 
of triangles whose vertical height is equal to Y W in elevation. 
Therefore, in Fig. 80, draw any horizontal line as T U, upon which 
place the various lengths M 1, M 2, M 3, etc.) 
Fig. 79) as shown by similar numbers on 
T U. From T U erect the line T S equal to 
the vertical height Y W (Fig. 79). Then 
draw the hypotenuses SI, S 2, S 3, etc., ie 
Fig. 80, which represent the true lengths of 
similar numbered lines in plan in Fig. 79. 
For the half pattern with seams on I O and 
P K in plan, take a tracing of D V W in elevation and place it 
as shown by D Y 7 in Fig. 81. Now using D as center, and with 
radii equal to the various slant lines in Fig. 80 from S 1 to S 7 
strike small arcs as shown from 1 to 7 in Fig. 81. Set the dividers 




342516 
Fig. 80. 



86 



SHEET METAL WORK 



equal to the spaces contained in O R, in Fig. 79, and starting from 
point 7, in Fig. 81, step from one arc to another until 1 is obtained. 
Then using 1 as center and E D (Fig. 79) as radius describe 
the avc D' in Fig. 81. With D as center and M I in plan in Fig. 




Fig. 81. 

79 as radius, draw another arc intersecting the one previously 
drawn at D'. Draw a line froml to D' to D in Fig. 81,7 1D'DV 
is the quarter pattern, and the left-hand side of the figure may be 
made by tracing the quarter pattern reversed as shown by Y C D" 
1' 7. Take the distance of the flange D A in elevation in Fig. 79 
and place it at right angles to the line D'D, DC,C D" as shown 
respectively by A" A', A A and A v A x , which completes the half 
pattern with laps allowed as shown 

The pattern for the collar E F G H in 
elevation in Fig. 79 is simply a straight 
strip of metal, equal to the circumference 
of O P R in plan. 

It is often the case that two unequal 
pipes are to be connected by means of a 
transition piece as shown by A in Fig. 82, 
the ends of the pipes being cut at right 
angles to each other. As the centers of 
both pipes are in one line when viewed in plan, making both 
halves of the transition piece equal, the problem then consists of 
developing a transition piece, from a round base to a round top 
placed vertically. Therefore in Fig. 83 draw 1 5 equal to 2 J inches, 
and at an angle of 45° draw 5 6 1| inches. At right angles to 1 5 
draw 6 10 4 inches long and draw a line from 10 to 1. On 1 5 draw 
.the semicircle 1 3' 5, and on 6 10 draw the semicircle 6 8' 10. 




SHEET METAL WORK 



87 



Divide both of these into equal spaces as shown, from which draw 
lines perpendicular to their respective base lines. Connect opposite 
points as shown by the dotted lines, and construct a diagram of 




8' 



'ST "^ 



~—j< 



2 3 45 



d 10 



Fig. 84. 

sections as shown in Fig. 84 whose bases and heights are equal to 
similar numbered bases and heights in Fig. 83. For example, take 
the distance 4 8 and place it as shown by 4 8 in Fig. 84, from which 
points erect the Y?rtical lines 4 4' and 8.8' equal to 4 4' and 8 8' in 
Fig. 83. Draw a line from 4' to 8', Fig. 84, which is the true 





Fig. 86. 

length on similar line in Fig. 83. For the pattern take the dis- 
tance of 1 10 and place it as shown by 1 10 in Fig. 85. Using 1 
as center, and 1 2', Fig. 83, as radius, describe the arc 2 in Fig. 85; 
intersect it by an are struck from 10 as center and 10 2', Fig. 84, 
as radius. Then using 10 9' in Fig. 83 as radius, and 10, Fig. 85, as 



88 



SHEET METAL WORK 



center, describe the arc 9, and intersect it by an arc struck from 2 
as center, and 2' 9', Fig. 84, as radius. Proceed in this manner 
using alternately as radii, first the divisions in the half profile 
1 3' 5, Fig. 83, then the length of the proper hypotenuse in Fig. 
84, then the divisions in 6 8' 10 in Fig. 83; then again the hypot- 
enuse in Fig. 84 until the line 5 6 in Fig. 85 has been obtained, 
which is equal to 5 6 in Fig. 83. Laps should be allowed for 
riveting and seaming as shown. 




PLAN 



Fig. 87. 



In Fig. 86 is shown a perspective of an offset connecting 
a round pipe with an oblong pipe, having rounded corners. 

The first step is to properly draw the elevation and plan as 
shown in Fig. 87. Draw the horizontal line A B equal to one 
inch, B 5' one inch, and from 5' at an angle of 45° draw 5' 6' equal 
to 2J inches and 6' C 1J inches. Make the diameter C D 2| inches 
and D f 0' 1| inches. Make Al'| inch and draw a line from 1' to 



4' 



SHEET METAL WORK 89 

10' which completes the elevation. Directly above the line A E 
draw the section of the oblong pipe, making the sides 1 1 and 5 5 
equal to 1^ inches, to which describe the semicircles on each end 
as shown. In similar manner draw the section on D C, which is 
shown by 6 8 10 8. A duplicate of the oblong pipe is also shown 
in plan by E F, showing that the centers of the pipe come in one 
line, making both halves symmetrical. 

The patterns for the pipes will first be obtained. Divide the 
semicircular ends of the oblong section into equal parts, in this 
case four, also each of the semicircles of the round pipe in similar 
number of parts as shown respectively from 1 to 5 and 6 to 10. Draw 
vertical lines from these intersections cutting the miter line of the 
oblong pipe at V 2' 3' 4' 5' and the miter line of the round pipe at 
6' 7 8' 9' and 10'. In line with A B draw 

BM, upon which place the stretchout of g ,2' 3 . 

the oblong pipe as shown by similar num- 9i— «•. r=f&^f^zZ^ 

bers; from B M drop vertical lines inter- — ~^TV 

secting the lines drawn parallel to B M 109 8 7 6 1234 

from similarly numbered points on 1' 5'. Fig. 88. 

Trace a line through points thus obtained, 

and PNO will be the pattern for the oblong pipe. Now take the 
stretchout of the round pipe, and place it on C H ; erect vertical lines 
as shown intersecting the lines drawn parallel to C H from similar 
intersections on 6' 10'. I J H C is the pattern for the round pipe. 

The transition piece 1' 5' 6' 10' will be developed by triangu- 
lation, and it is usual to obtain true sections on the lines 1' 5' and 
6' 10' ; however, in this case it can be omitted because we have the 
true lengths of the various divisions on the lines 1' 5' and 6' 10' in 
the miter cuts in P and L respectively. 

The next step is to obtain a diagram of sections giving the 
true lengths, for which proceed as follows : Connect opposite points 
in elevation as shown from 1' to 9' to 2' to 8' to 3' etc., as shown. 
For example draw center lines through the oblong and round sec- 
tions as shown by a b and c d respectively, and take the length of 
1' 10' in elevation and place it as shown from 1 to 10 in Fig. 88. 
From 1 draw the vertical line 1 1' equal to the height of 1 in the 
oblong section in Fig. 87 above the center line a b. As point 10 
in plan has no height, it falls on the center line c d in plan, then 



90 SHEET METAL WORK 

draw a line from 1' to 10 in Fig. 88. Now take the distance from 
1' to 9' in elevation, Fig. 87, and place it as shown from 1 to 9 in 
Fig. 88. Erect the lines 1 1' and 9 9' equal to points 1 and 9 in 
the oblong and round sections in Fig. 87, measured respectively 
from the lines a b and c d. Draw a line from 1' to 9' in Fig. 87. 
Proceed in this manner until all of the sections are obtained. For 
the pattern proceed as shown in Fig. 89, in which draw any verti- 
cal line as e 10 equal to 1' 10' in elevation in Fig. 87. Now, with 
one-half of 1 1 in pattern Pas^l as radius, and e in Fig. 89 as 
center, describe the arc 1 which is intersected by an arc struck 
from 10 as center and 10 1', in Fig. 88 as radius. With radius 
equal to 10" 9" in pattern L in Fig. 87, and 10 in Fig. 89 as center 
describe the arc 9, which is intersected by an arc struck from 1 as 
center and 1' 9', in Fig. 88 as radius. Now, using as radius 1" 2" 
in pattern P in Fig. 87 and 1 in Fig. 89 as center, describe the 
arc 2 which is intersected by an arc struck from 9 as center and 
9' 2' in Fig. 88 as radius. 

Proceed in this manner, using alternately as radii, first the 
divisions in the pattern cut I J, Fig. 87, then the length of the 
slant lines in Fig. 88, the divisions in the cut O N in Fig. 87, then 
again the slant lines in Fig. 88 until the line 5 6 in pattern, Fig. 
89, has been obtained. Then using 5 as center and 1 e in P, Fig. 
87, as radius, describe the arc e in Fig. 89, and intersect it by an 
arc struck from 6 as center and 6' 5' in elevation in Fig. 87 as 
radius. Draw lines through the various intersections in Fig. 89; 
10 e e' 6 is the half pattern. By tracing it opposite the line e 10, 
as shown by e V 5' e" 6' 10, the whole pattern, e' e e" 6' 10 6, 
is found. Laps should be allowed on all patterns for seaming or 
riveting both in Figs. 87 and 89. 

In Fig. 90 is shown a perspective view of a three-way branch 
round to round, the inlet A being a true circle, and the outlets B, C, 
and D also being true circles, the centers of which are in the same 
vertical plane, thus making both sides of the branch symmetrical. 

First draw the elevation and the various sections as shown in 
Fig. 91. Draw the center line a b. From b draw the center line 
of the branch C at an angle of 58° as shown by b d. Make the 
center lines a b and b d each 3^ inches long. Make the half 
diameter of the branch B at the outlet | inch, and the full diam- 



SHEET METAL WORK 



91 



eter of the branch C at the outlet 1^ inches placed on either side 
of and at right angles to the center lines. Draw a line from e toy, 
and with * and h as centers and radii equal to | inch draw arcs 
intersecting each other at c. Draw lines from i to c to h. In 
sic alar manner obtain A and the opposite half of B. A B C is 
the elevation of the three branches whose sections on outlet lines 
are shown respectively by G F and E and whose section on the 
inlet line is shown by D. 

The next step is to obtain a true section on the miter line or 
line of joint b c. Knowing the height b c and the width at the 




Fig. 89 



bottom, which is equal to the diameter of D, the shape can be 
drawn at pleasure as shown in Fig. 92, b c is drawn equal to b c, 
Fig. 91, while b d and b a are equal to the half diameter D in Fig. 
91. Now through a c dm Fig. 92 draw the profile at pleasure as 
shown, which represents the true section on c b in Fig. 91. 

As the side branches A and G are alike, only one pattern will 
be required, also a separate pattern for the center branch both of 
which will be developed by triangulation. To obtain the measure- 
ments for the sections for the center branch B, proceed as shown 
in Fig. 93 where 1 4 5 8 is a reproduction of one-half the branch 
B in Fig. 91. As the four quarters of this center branch are alike 
unly one quarter pattern will be developed; then, if desired, the 
quarter patterns can be joined together, forming one pattern. Now 



92 



SHEET METAL WOEK 



take a traciDg of c b a, Fig. 92, and place it on the line 5 8 as 
shown in Fig. 93. Similarly take a tracing of the quarter profile 
F in Fig. 91 and place it on the line 4 1 in Fig. 93. Divide the 
two profiles V 4 and 5 8' each into the same number of spaces as 
shown respectively by points 1' 2' 3' 4 and 5 6' 7' 8', from which 
points at right angles to their respective base lines 1 4 and 
5 8 draw lines intersecting the base lines at 1 2 3 4 and 5 6 7 8. 
Now draw solid lines from 3 to 6 and 2 to 7 and dotted lines from 
3 to 5, 2 to 6, and 1 to 7. These solid and dotted lines represent 




% i ! 



5 

A 






yr- 



2 * 



---a 



Fig. 91. Fig. 92. Fig. 98. 

the bases of the sections whose altitudes are equal to the various 
heights of the profiles in Fig. 93. The slant lines in Fig. 94 rep- 
resent the true distances on similar lines in Fig. 93, as those in 
Fig. 95 represent the true distances on dotted lines in Fig. 93. 

For the pattern take the length of V 8', Fig. 94, and place it 
as shown by 1 8 in Fig. 96, and using 8 as center and 8' 7' in 
Fig. 93 as radius draw the arc 7, which intersect by an arc struck 
from 1 as center and 1' 7' in Fig. 95 as radius. Then using V 2' 
in Fig. 93 as radius draw the arc 2, which intersect by an arc 
struck from 7 as center and 7' 2' in Fig. 94 as radius. Proceed 
va this manner until the line 4 5 in Fig. 96 has been obtained^ 



SHEET METAL WORK 



93 



which equals 4 5 in Fig. 93. Trace a line through points thus 
obtained in Fig. 96, then will 14 5 8 1 give the quarter pattern. 

If the pattern is desired in one piece trace as shown by 
similar figures, to which laps must be allowed for riveting. 

As the two branches A and C in Fig. 91 are alike, one pat- 
tern will answer for the two. Therefore let 1 7 8 11 14 in Fig. 
97 be a reproduction of the branch C in Fig. 91. Now take a trac- 
ing of a b c in Fig. 92 and place it as shown by 11' 11 8 in Fig. 
97 ; also take a tracing of the half section E and the quarter sec- 
tion D in Fig. 91 and place them as shown respectively by 1 4' 7 and 




876 3 2 I 

Fig. 94. 



Fig. 96. 



I 2 3 5 67 
Fig. 95. 



11 11' 14 in Fig. 97. Now divide the two lower profiles 8 11 and 
11' 14 each into 3 equal parts, and the upper profile 7 4' 1 into 6 
equal parts as shown by the small figures 8 to 11', 11' to 14 and 1 
to 7. From these points, at right angles to the various base lines, 
draw lines, intersecting the base lines as shown by similar num- 
bers. Draw solid and dotted lines as shown, and construct the 
sections on solid lines as shown in Fig. 98 and the sections on 
dotted lines as shown in Fig. 99 in precisely the same manner as 
described in connection with Figs. 94 and 95. 

In Fig. 100 is shown the pattern shape (to which laps must 
be allowed for riveting) obtained as was the development of Fig. 
96. First draw the vertical line 1 14, Fig. 100, equal to 1 14 in 
Fig. 97. Then use alternately as radii, first the divisions in 1 4' 7 in 
Fig. 97, the proper slant line in Figs. 98 and 99 and the divisions 
in 11' 14 until the line 4 11, Fig. 100, is obtained. Starting from 



94 



SHEET METAL WORK 



the point 11 use as radii in their regular order the distances marked 
off between 11' and 8, Fig. 97, then the proper slant lines in Figs. 
98 and 99, the distances shown in the semicircle, 1 4' 7, Fig. 97, 
antil the line 7 8, Fig. 100, is drawn equal to 7 8, in Fig. 97. Then 







\t it 



id 






ii 3 'i iek ttBtf 

n I -LfX' 1 lilt 
6 5 13 4 12 1234 149 6 6 5 101342 



Fig. 97. 



Fig. 98. 



Fig. 99. 



1 7 8 11 14, Fig. 100, will be the half pattern. If the pattern is 
desired in one piece trace 1 7' 8' 11' 14 opposite the line 1 14 
as shown. 

In Fig. 101 is shown a perspective view of a two-branch fork 
oval to round, commonly used as breeching for two boilers. As 




Fig. 100. 




Fig. 101. 



both halves of the fork are symmetrical the pattern for one will 
answer for the other. 

While the side elevation shown in Fig. 102 ia drawn com- 
plete, it is only necessary in practice, to draw one half as follows, 
p,nd then, if desired, th# other half elevation can be traced opposite 



SHEET METAL WORK 



95 



to the center line E J. First draw J B, 1^ inches, equal to the 
half diameter of the outlet, and the vertical center height J V, 2^ 
inches. Establish the height of the joint J E one inch, and the 
desired projection YD on the base line 1£ inches. Draw the 
length of the inlet D C 2| inches, and draw a line from C to B 
and D to E. Draw a similar figure opposite the line J E, and 
A B C D E F G shows the side elevation of the fork. In their 
proper position below A B draw the sections M and N whose 
semicircular ends are struck from a b e and d with radii equal to 
■| inch. Now draw an end elevation in which the true section on 




e 

END 
ELEVATION 



Fig. 102. 

J E is obtained. Draw the center line f e and extend the lines 
A B and G C in elevation as A P and G S. Take the half diam- 
eter L J and place it on either side of ef as shown by OP. In a 
similar manner take the half diameter of the section ~N &s d i and 
place it on either side of ef as shown by R S. Then OPSR 
shows the end elevation. Draw E T intersecting ef at T. Now 
draw the curve O T P, which in this case is struck from the center 
U, being obtained by bisecting the line O T, It should be under- 
stood that the curve O T P, which represents the true section osa 
J E, can be made any desired shape, but when onoe drawn, repre- 
sents a fixed line. 



96 



SHEET METAL WORK 



The pattern will be developed by triangulation, for which 
diagrams of sections must be obtained from which to obtain meas- 
urements. These sections are obtained as follows: In Fig. 103 
1 4 5 12 13 is a reproduction of J B C D E, Fig. 102. Reproduce 
the quarter profile H L I, the half profile O T, and the half profile 
m no as shown by 1' 1 4, 1" 13 1 and 12 9' 8' 5 in Fig. 103. 
Divide the round ends in a each into 3 parts and the profiles b and 
c also each into 3 spaces, as shown by the figures. Drop lines 
from these figures at right angles to the base lines from 1 to 15 as 
shown and draw solid and dotted lines in the usual manner. While 
in some of the previous problems only dotted lines were drawn, we 





123 1 1514 II 10 9 678 

Fig. 104. 



2' 

231514 II 109678 

Fig. 105. 



have drawn both solid and dotted lines in this case, in order to 
avoid a confusion of sections. A diagram of sections on solid lines 
in Fig. 103 is shown in Fig. 104, the figures in both correspond- 
ing; while Fig. 105 shows the true sections on dotted lines. The 
method of obtaining these sections has been described in connection 
with other problems. 

For the pattern draw any vertical line as 4 5, Fig. 106, equal 
to 4 5 in Fig. 103. Then with 5 6', Fig. 103, as radius and 5 in 
Fig. 106 as center draw the arc 6, intersecting it by an arc struck 
from 4 as center and 4 6', Fig. 105, as radius. Then using 4 3', 
Fig. 103, as radius, and 4 in Fig. 106 as center, describe the arc 3, 
intersecting it by an arc struck from 6 as center and 6' 3' in Fig. 
104 as radius. Proceed in this manner, using alternately as radii, 
first the divisions in a in Fig. 103, then the slant lines in Fig. 
105; the divisions in a in Fig. 103, then the slant lines in Fig. 



SHEET METAL WORK 



97 



104, until the line 1 8, Fig. 106, is obtained. Now using 8 as 
center and 8' 9', Fig. 103, as radius draw the arc 9 in Fig. 106, 
intersecting it by an arc struck from 1 as center and 1" 9', Fig. 
104, as radius. Then starting at 1 in Fig. 106 use alternately as 
radii, first the divisions in b in Fig. 103, then the slant lines in 
Fig. 105, the divisions in a in Fig. 103, then the length of the 
slant lines in Fig. 104 until the line 12 13 is obtained in Fig. 106, 
which equals 12 13 in Fig. 103. Trace a line through points thus 
obtained in Fig. 106, then will 4 1 13 12 9 8 5 be the half pattern. 
If the pattern is desired in one piece, trace this half opposite the 
line 4 5 as shown by V 13' 12' 9' 8', allowing laps for riveting. 

In Fig. 107 is shown a perspective view of a tapering flange 
around a cylinder passing through an inclined roof, the flange 




Fig. 107. 



being rectangular on the roof line. The problem will be developed 
by triangulation, a plan and elevation first being required as shown 
in Fig. 108. 

First draw the angle of the roof A B at an angle of 45°, 
through which draw a center line O D. From the roof line A B 
on the center line set off a b equal to 4 inches and through b draw 
the horizontal line E F, making B F and B E each one inch. 
Through d on the center line draw the horizontal line G H, making 
d H and d G each two inches. From H and G erect perpendiculars 
intersecting the roof line at K and L. Then draw lines from E to 
K and F to L, completing the elevation. Construct the square in 
plan making the four sides equal to G H. Bisect H I and draw 
the center line c e intersecting the vertical center at d'. Then with 
radiui equal to b F or b E in elevation and d' in plan as center, 



98 SHEET METAL WORK. 

draw the circle 14 7 4' representing the horizontal section on E F 
in elevation, while G H IJ is the horizontal section on K L in 
elevation. As the circle in plan is in the center of the square 
making the two halves symmetrical it is only necessary to divide the 
semicircle into equal spaces as shown from 1 to 7 and draw lines 



o--' 




Fig. 108. 

from 1, 2, 3 and 4 to G, and 4, 5, 6 and 7 to H. Then will the 
lines in 1 G 4 and 4 H 7 represent the bases of triangles which 
will be constructed, whose altitudes are shown respectively by the 
vertical heights in K E and L F in elevation. Therefore draw hori- 
zontal lines through E F, K, and L as shown by F O, "K N, and L M. 
From any point as R and T on F O, draw the perpendiculars R S 
and T U respectively, meeting the horizontal lines drawn from L 
and K. Now take the various lengths in plan as Gl, G2, G3, and 



SHEET METAL WOEK 



99 



G4 and place them on the line F O as shown by Tl, T2, T3 and T4, 
from which points draw lines to U which will represent the true 
lengths on similar lines in plan. In similar manner take the dis- 
tances in plan from EL to 4, to 5, to 6, to 7, and place them on the 
line F O, from R to 4, to 5, to 6, to 7, from which points draw lines 
to S which represent the true lengths on similar lines in plan. 

For the pattern take the distance F L in elevation and place 
it on the vertical line 7' L in Fig. 109. At right angles to 7' L 
draw L S equal to c H or c I in plan, Fig. 108. Draw the dotted 




line from 7' to S in Fig. 109, which should be equal to S 7 in W 
in Fig. 108. Now with radii equal to S 4, and S | and S, Fig. 
109, as center, draw the arcs indicated by similar numbers. The 
dividers should equal the spaces in the semicircle in plan in Fig. 
108, and starting at 7' in Fig. 109, step from arc to arc of corre- 
sponding numbers as shown by 6', 5', 4'. Draw a dotted line 
from 4' to S. Then using S as center and L K in elevation, Fig. 
108, as radius, describe the arc U in Fig. 109, intersecting it by an 
arc struck from 4' as center and U 4, Fig. 108, as radius. Now 
using U ^, and U § in X as radii, and U, Fig. 109, as center, 
describe arcs having similar numbers. Again set the dividers 
equal to the spaces in plan in Fig. 108, and starting from 4' in 
Fig. 109 step to corresponding numbered arcs as shown by 3', 2', 1'. 



100 



SHEET METAL WORK 



Draw a dotted line from 4' to U to 1'. With K E in elevatioD, 
Fig. 108, as radius, and Y in Fig. 109 as center, describe the 
arc e intersecting it by an arc struck from U as center an(? tr e in 
plan in Fig. 108 as radius. Draw a line connecting S, U, e, and 1'. 
T 4' 1' e (J S L T shows the half pattern, which can be traced 
opposite the line 7' L to complete the full pattern as shown by 
T 4" 1" e IP S' L. 

One of the difficult problems often encountered by the sheet 
metal worker is that of a cylinder joining a cone furnace top at 
any angle. The following problem shows the principle to be 
applied, no matter what size the furnace top has, or what eij. > pipe 
is used, or at what angle the pipe is placed in plan or elevation, the 
principles being applicable under any conditions. 

Fig. 110 shows a view of a cyl- 
inder intersecting a conical fur- 
nace top, the top being placed to 
one side of the center of the top. 
A B C D represents a portion of 
the conical top, intersected by the 
cylinder EFGH, the side of the 
cylinder E I to intersect at a 
given point on the conical top as 
at H. This problem presents an 
interesting study in projections, 
intersections, and development, to 
which close attention should be 
given. 
In Fig. Ill first draw the center line A X. Then draw the 
half elevation A B C D, making A B 1| inches, C D 3| inches 
and the vertical height A D 2| inches. Draw the line from B to 
C. Directly below C D draw the one-quarter plan using Z as 
center, as shown by Z C 1 D 1 and in line with A B of the elevation 
draw the quarter plan of the top as Z B 1 A 1 . Let a in the eleva- 
tion represent the desired distance that the side of the cylinder is 
to meet the cone above the base line as H in Fig. 110. From a, 
parallel to C D in Fig. Ill, draw a b. Then from a drop a ver- 
tical line intersecting the line Z O in plan at a'. Then using Z as 
center and Z a' as radius, describe the quarter circle a' ?/. Z a' b' 




Fig. 110. 



SHEET METAL WORK 



101 



in plan represents the true section on the horizontal plane a h in 
elevation. Now locate the point where the side of the cylinder as 
H in Fig. 110 shall meet the arc a' h' in plan, Fig. Ill, as shown 




Fig. 111. 



102 SHEET METAL WORK 

at 3". Through 3" draw the horizontal line intersecting the center 
line at K 1 , the outer arc at M 1 and extend it indefinitely to 3. 
From 3 erect the perpendicular equal to the diameter of the cylin- 
der, or 1| inches, bisect it and obtain the center c. Using c as 
center with c 7 as radius, describe the profile of the cylinder as 
shown, and divide it into equal parts from 1 to 8. From these 
points draw lines parallel to 3 K 1 , intersecting the outer arc D 1 C 1 
at N 1 O 1 P K 1 and the center line Z X at I 1 , G 1 , E 1 , A 1 . With Z 
as center and the various intersections from K 1 to A 1 as radii, 
describe the arcs K 1 L 1 , I 1 J 1 , G 1 H 1 , E 1 F 1 , and A 1 B 1 . From the 
intersection B 1 , FyH 1 , J 1 , L 1 erect vertical lines into the elevation 
intersecting the side of the cone B C as shown by similar letters 
B F H J L. From these points draw horizontal lines through the 
elevation as shown respectively by A B, E F, G H, I J, and K L. 
These lines represent a series of horizontal planes, shown in plan 
by similar letters. For example, the arc E 1 F 1 in plan represents 
the true section on the line E F in elevation, while the arc G 1 H 1 
is the true section on the line G H in elevation, etc. 

The nest step is to construct sections of the cone as it would 
appear, if cut by the lines shown in plan by K 1 M 1 , I 1 N" 1 , G 1 O^E 1 
P 1 , and A 1 R 1 . To obtain the section of the cone in elevation on 
the line A 1 R 1 in plan, proceed as follows: At right angles to the 
line A 1 R 1 and from the intersections on the various arcs, draw lines 
upward (not shown) intersecting similar planes in elevation cor- 
responding to the arcs in plan. A line traced through intersections 
thus obtained in elevation as shown from A to R, will be the true 
section on the line A 1 R 1 in plan. For example, the line K 1 M 1 of 
the cylinder intersects the arcs at K 1 3" and M l respectively. From 
these intersections, erect vertical lines intersecting KL,J«, and D C 
in elevation at K, 3', and M respectively. Trace a curve through 
these points, then will K 3' M be the section of the cone if cut on 
the line K 1 M 1 in plan. In similar manner obtain the other sections. 
Thus the section line E P, G O, and I N in elevation, represent 
respectively the sections if cut on the lines E 1 P 1 , G 1 O 1 , and I 1 N 1 
in plan. Now from the given point 3" in plan erect a line which 
must meet the intersection of the plane h a and section KM in 
elevation at 3'. From 3' at its desired angle, in this case 45°, draw 
the line 3' 7. At any point as d at right angles to 3' 7 draw the 



SHEET METAL WORK 10S 

line 1 5 through d, making d 5 and d 1 each equal to half the 
diameter of the cylinder shown in plan. With dh as radius and<i& 
as center draw the profile of the cylinder in elevation, and divide it 
into the same number of parts as shown in C in plan, being careful 
to allow the circle d in elevation to make a quarter turn, bringing 
the number 1 to the top as shown. 

The next operation is to obtain the miter line or line of joint 
between the cylinder and cone in elevation. By referring to the 
plan it will be seen that the point 7 in the profile c lies in the plane 
of the section A 1 R 1 . Then a line from the point 7 in the profile 
d in elevation, drawn parallel to the lines of the cylinder, must cut 
the section A E, which corresponds to the plane A 1 E, 1 in plan as 
shown by 7' in elevation. The points 6 and 8 in the profile e in 
plan, are in the plane at the section E 1 P 1 , then must the corre- 
sponding points 6 and 8 in the profile d in elevation, intersect the 
section E P as shown by 6' and 8'. As the points 1 5, 2 4, and 3 
in the profile c in plan, are in the planes of the sections G 1 O 1 , I 1 N 1 , 
and K 1 M 1 respectively, the corresponding points 1 5, 2 4, and 3 in 
the profile d in elevation must intersect the sections G O, I N, and 
K M respectively at points 1' 5', 2' 4', and 3' as shown. Trace a 
line through these points, which will show the line of intersection 
between the cone and cylinder. 

For the pattern for the cylinder, proceed as follows : At right 
angles to the line of the cylinder in elevation, draw the line T U 
upon which place the stretchout of the profile d as shown by sim- 
ilar figures on T U. In this case the seam of the pipe has been 
placed at 1 in d. Should the seam be desired at 3, 5 or 7, lay 
off the stretchout on T U starting with any of the given numbers. 
At right angles to U T from the small figures 1 to 1 draw lines 
which intersect with lines drawn from similar numbered intersec- 
tions in the miter line in elevation at right angles to 1' 1, result- 
ing in the intersections 1 to 5° to 1° in the pattern. Trace a line 
through points thus obtained, then will U V W T be the develop- 
ment for the cylinder to which laps must be allowed fc>r riveting 
to the cone as shown in Fig. 110 and seaming the joint T W in 
pattern in Fig. 111. 

While the pattern for the cone is obtained the same as in 
ordinary flaring ware, the method will be described for obtaining 



104 



SHEET METAL WORK 



the pattern for the opening to be cut into the cone. Before this 
can be done a plan view of the intersection between the pipe and 
cone must first be obtained as follows: From the various in- 
tersections 1' to 8' in elevation drop vertical lines intersecting 
lines drawn from similar numbers in the profile c in plan, thus 
obtaining the intersections 1" to 8" through which a line is traced 
which is the desired plan view. 

For the pattern for 
the opening in the 
cone, the outline of 
the half elevation and 
one-quarter plan with 
the various points of 
intersections both in 
plan and elevation in 
Fig. 112 is a repro- 
duction of similar 
parts in Fig. Ill, and 
has been transferred 
to avoid a confusion of 
lines which would 
otherwise occur in ob- 
taining the pattern. 
Parallel to DC in Fig. 
112 from the various 
intersections 1' to 8' 
draw lines intersect- 
ing the side of the 
cone B C from 1 to 8. 
Through the various 
intersections 1" to 8" 
in plan from the apex 
Z draw lines intersecting the outer curve from 1° to 8° as shown. 
Extend the line C B in elevation until it meets the center line D A 
extended at E. Then using E as center, with E C and E B as radii 
draw the arcs C F and B 11 respectively. At any point as 2 X on 
the arc C F lay off the stretchout of the various points on D 1 C 1 in 
plan from 2 e t >> 6° as shown by similar figures on C F as shown 




SHEET METAL WORK 105 

from 2 X to 6 X . From these points draw radial lines to the apex 
E, and intersect them by arcs struck from E as center whose radii 
are equal to the various intersections on B C having similar numbers. 
Thus arc 4 intersects radial line 4 X at 4 V ; arcs 3, 5, and 2 intersect 
radial lines 3 X , 5 X , and 2 X at 3 V , 5 V , and 2 V , and so on. Trace a 
line through points thus obtained as shown from l v to 8 V which is 
the desired shape. If a flange is desired to connect with the cylin- 
der, a lap must be allowed along the inside of the pattern. 

COPPERSfllTH'S PROBLEMS. 

In the five problems which will follow, particular attention i« 
given to problems arising in the coppersmith's trade. While all 
the previous problems given in the course can be used by the cop- 
persmith in the development of the patterns where similar shapes 
are desired, the copper worker, as a rule, deals mostly with ham- 
mered surfaces, for which flaring patterns are required. The prin- 
ciples which will follow, for obtaining the blanks or patterns for 
the various pieces to be hammered, are applicable to any size or 
shape of raised work. The copper worker's largest work occurs in 
the form of brewing kettles, which are made in various shapes, to 
suit the designs of the different architects who design the work. 
In hammering large brewing kettles of heavy copper plate, the 
pieces are developed, hammered, and fitted in the shop, then set 
together in the building, rope and tackle being used to handle the 
various sections for hammering, as well as in construction at the 
building. While much depends upon the skill the workman has 
with the hammer, still more depends upon the technical knowledge 
in laying out the patterns. 

In all work of this kind the patterns are but approximate, but 
no matter what size or shape the work has, the principles contained 
in the following problems are applicable to all conditions. 

In Fig. 113 is shown a perspective of a sphere which is to be 
constructed of horizontal sections as shown in Fig. 114, in which 
for practice draw the center line A B, on which, using a as center, 
and with radius equal to 2^ inches, describe the elevation of the 
sphere BCDE. Divide the quarter circle D C into as many 
spaces as the hemi-sphere is to have sections, as shown by C F G D. 
From these points draw horizontal lines through the eleyation, as 



106 



SHEET METAL WORK 



shown by C E, F H, and G I. ISow through the extreme points 
as E H, H I, and I D draw lines intersecting the center line B A 
at J, X, and D respectively. For the pattern for the first section 
Z, take D I as radius, and using D 1 in Z 1 as center, describe the 
circle shown. For the pattern for the second section Y, use X I 
and X H as ladii, and with X 1 as center draw the arcs I 1 I 2 and H 2 




Fig. 113. 



Fig. 114. 



H 3 . From any point as H 3 draw a line to the center X 1 . It now 
becomes necessary to draw a section, from which the true length 
of the patterns can be obtained. Therefore with b F as radius, 
describe the quarter circle F L, which divide into equal spaces, as 
shown by the figures 1 to 5. Let the dividers be equal to one of those 
spaces and starting at H 3 on the outer arc in Y 1 step off four times 
the amount contained in the quarter section F L, as shown from 1 



SHEET METAL WORK 



107 




to 5 to 1 to 5 to 1 in Y 1 . From 1 or H 2 draw a line to K 1 . Then 
will H 2 I 2 I 1 H 3 be the pattern for the section Y in elevation. 

For the pattern for the third section, use J as center, and with 
radii equal to J H and J E draw the arcs H H 1 and E E l . Now 
set the dividers equal to one of the equal spaces in F L and starting 
from H. set off four times the amount of L F as shown from 1 to 5 
to 1 to 5 to 1 on the inner curve H H 1 . From the apex J through 
H 1 draw a line intersecting the outer curve at E\ E E 1 H 1 H 
shows the pattern for the center section. It will be noticed in the 
pattern X 1 we space off on the inner curve, while on the pattern 
Y 1 we space off on the outer curve. These two curves must contain 
the same amount of material as 
they join together when the ball is 
raised. To all of the patterns laps 
must be allowed for brazing or 
soldering. The patterns shown 
are in one piece ; in practice where 
the sphere is large they are made 
in a number of sections. 

In Fig. 115 is shown the per- 
spective view of a circular tank whose outline is in the form of 
an ogee. The portion for which the patterns will be described is 
indicated by A A, made in four sections, and riveted as shown 
by a b c d. 

Fig. 116 shows how the pattern is developed when the center 
of the ogee is flaring as shown from 3 to 4 in elevation. First 
draw the elevation ABCD, making the diameter of A B equal 
to 7 inches, the diameter of D C 4 inches, and the vertical height 
of the ogee 1| inches. Through the center of the elevation draw 
the center line/" h, and with any point upon it as i, draw the half 
plan through A B and C D in elevation as shown respectively by 
E F and HG. Now divide the curved parts of the ogee into 
equal spaces as shown from 1 to 3 and 4 to 6. Draw a line through 
the flaring portion until it meets the center line/* h atj. j will, 
therefore, be the center with which to strike the pattern. Take 
the stretchout of the curve from 3 to 1 and 4 to 6 and place it on 
the flaring line from 3 to 1' and 4 to 6' as shown by the figures. 
Then will 1' 6' be the stretchout for the ogee. It should be under- 



Fig. 115. 



108 



SHEET METAL WORK 



^tood that no hammering is done to that part shown from 3 to 4. 
The portion shown from 3 to 1' is stretched to meet the required 
profile 3 2 1, while the lower part 4 to 6' is raised to conform with 
the lower curve 4 5 6. Therefore, knowing that the points 3 and 4 
are fixed points, then from either of these, in this case point 4, 




Fig. 116. 

drop a vertical line intersecting the center line E F in plan at a. 
Then with * as center and ia as radius, describe the quarter circle a e, 
and space it into equal parts as shown by a> &, c, d, e, which represent 
the measuring line in plan on the point 4 in elevation. Using j 
as center, and j 6', j 4, j 3 and j V as radii, draw the arcs 1"-1'", 
3"-3'", 4"-4'" and 6"-6'" as shown. From 1" draw a radial line to j 
intersecting all the arcs as shown. Now starting at 4" step off on 



SHEET METAL WORK 



109 



the arc 4" A'" twice the stretchout of the quarter circle ae &s shown 
by similar letters a to e to a' in pattern. From j draw a line 
through a' intersecting all of the arcs as shown. l"-l"'-6'"-6" 
shows the half pattern for the ogee. 

While in the previous 
problem the greater part of 
the ogee was flared, occasion 
may arise where the ogee is 
composed of two quarter cir- 
cles struck from centers as 
shown in Fig. 117. First 
draw the center line A B, 
then draw the half diameter 
of the top C 1 C equal to 3£ 
inches and the half diameter 
E D If inches. Make the 
vertical height of the ogee 1\ 
inches, through the center of 
which draw the horizontal line 
a b. From C and D draw ver- 
tical lines intersecting the 
horizontal line a b, at a and b 
respectively. Then using a 
and b as centers with radii 
equal respectively to a C and 
b D draw the quarter circles 
shown completing the ogee. 
In the quarter plan below 
which is struck from the cen- 
ter F, G J and H I are sec- 
tions respectively on D E and 
C C 1 in elevation. The meth- 
ods of obtaining the patterns in 
this case are slightly different 
than those employed in the previous problems. The upper curve 
shown from C to c will have to be stretched, while the lower curve 
shown from c to D will have to be raised. Therefore in the stretch- 
out of the pattern of the upper part from 1' to 3 and 3 to 5 the 




Fig. 117. 



110 SHEET METAL WORK 

edges must be stretched so as to obtain more material to allow the 
metal to increase in diameter and conform to the desired shape 
shown from 1 to 3 and 3 to 5. In the lower curve the opposite 
method must be employed. While in the upper curve the edges 
had to be stretched to increase the diameters, in the lower curve 
the edges must be drawn in by means of raising, to decrease the 
diameter, because the diameters to the points 5" and 9' are greater 
than to points c and d. 

To obtain the pattern for the upper curve C c which must be 
stretched, draw a line from C to c; bisect it and obtain d, from 
which erect the perpendicular d 3 intersecting the curve at 3. 
Through 3 draw a line parallel to c intersecting the center line 
A B at m. Now divide the curve C c into equal spaces as shown 
from 1 to 5 and starting from the point 3 set off on the line just 
drawn on either side of 3 the stretchout shown from 3 to 1' and 3 
to 5'. 1' 5' shows the amount of material required to form the 
curve C c. In this case 3 represents the stationary point of the 
blank on which the pattern will be measured. Therefore from 3 
drop a vertical line intersecting the line F H at 10. Then using 
F as center and F 10 as radius, describe the arc 10 16, and divide 
it into equal spaces as shown from 10 to 16. Now with radii equal 
to m 5', m 3 and m 1', Fig. 117, and with m in Fig. 118 as cen- 
ter, describe the arcs 5 5', 3 3' and 1 1'. Draw the radial line m 1 
intersecting the two inner arcs at 3 and 5. As the arc 3 3' repre- 
sents the stationary point 3 in elevation in Fig. 117, then set the 
dividers equal to the spaces 10 16 in plan and step off similar 
spaces in Fig. 118 on the arc 3 3', starting at 3 as shown by simi- 
lar numbers 16 to 10. Through 10 draw a line to the apex m, 
intersecting the inner curve at 5' and the outer curve at 1', 
1 1' 5' 5 is the quarter pattern for the upper curve or half of the 
ogee, to which laps must be allowed for riveting and brazing. 

For the pattern for the lower curve in elevation in Fig. 117 
draw a line from c to D; bisect it at e and from e erect a perpen- 
dicular intersecting the curve at 7. From 7 draw a horizontal line 
intersecting the center line at/*. Now the rule to be followed in 
" raising " is as follows : Divide the distance from e to 7 into as 
many parts, as the half diameter F 7 is equal to inches. In this 
case If equals 2^ inches; (any fraction up to the -| inch is not 



SHEET METAL WOKK 



111 



taken into consideration, but over ^ inch one is added). Therefore 
for 2| inches use 2. Then divide the distance from e to 7 into 
two parts as shown at * and through * parallel to c D draw a line 
as shown intersecting the center line at K". Now divide the curve 
e to D into equal spaces as shown by the figures 5 to 9. Let off 
on either side of * the stretchout from 5 to 9 as shown from 5" to 




\ PATTERN FOR LOWER 
\ HALF OF OGEE / 

\ \ j / / 

\ r / 

v I / 

\ I / 

\ I / 

\ 1 ' 

Fig. 118. 

9'. From * drop a vertical line intersecting F H in plan at 23. 
Then using F as center draw the arc 23 17 as shown, which rep- 
resents the measuring line in plan on * in the stretchout. 

The student may naturally ask, why is i taken as the measuring 
line in plan, when it is not a stationary point, for when "raising" i 
will be bulged outward with the raising hammer until it meets 
the point 7. In bulging the metal outward, the surface at i 
stretches as much as the difference between the diameter at * and 



112 



SHEET METAL WOKK 



7. In other words, if the measuring point were taken on 7 it 
would be found that after the mould was " raised " the diameter 
would be too great. But by using the rule of dividing e 7 into as 
many parts as there are inches in/* 7 the diameter will be accurate 
while this rule is but approximate. In this case e 7 has only been 
divided into two equal parts, leaving but one point in which a line 
would be drawn througn parallel to c D. Let us suppose that the 
semi-diameter 71/ is equal to eleven inches. Then the space from 

& to 7 would be divided into just so 
many parts, and through the first part 
nearest the cove the line would be drawn 
parallel to c D and used as we have 
used i. Now with radii equal to n 9', 
ni, and n 5" and n in Fig. 118 as center, 
describe the arcs 5" 5'" i i' and 9 9'. 
From any point as 5" draw a line to n 
intersecting all the arcs shown. Now 
take the stretchout from 17 to 23 in 
plan, Fig. 117, and starting from 17 in 
Fig. 118 mark off equivalent distances 
on the arc i i' as shown. Draw a line 
through 23 to the apex n, intersecting 
the inner and outer arcs at 9' and 5'". 
Then will 9 5" 5'" 9' be the greater pat- 
tern for the lower part of the ogee. 

Another case may arise where the 
center of the ogee is vertical as shown from c to d in Fig. 119 in 
A B. In this case the same principles are applied as in Fig. 117; 
the pattern for c d in Fig. 119 being a straight strip as high as 
c d and in length equal to the quarter circumference c' c" in plan 
in Fig. 117 which is the section on e in elevation. These rules 
are applicable to any form of mould as shown in Fig. 119, by 
e,f, h, and/. The bead i in j would be made in two pieces with 
a seam at i as shown by the dotted line, using the same method 
as explained in connection with cDin elevation in Fig. 117. 

The coppersmith has often occasion to lay out the patterns 
for curved elbows. While the sheet metal worker lays them &m 




SHEET METAL WOKK 



113 



in pieces, the coppersmith's work must form a curve as shown in 
Fig. 120 which represents a curved elbow of 45°. 

In Fig. 121 is shown how an elbow is laid out having 90 3 , 
similar principles being required for any degree of elbow. First 
draw the side elevation of the elbow as shown by A B C D, mak- 




Fig. 121. 



Fig. 120. 



ing the radius E B equal to 4| inches ana the diameter B C 2 
inches. Bisect C B at K. Then with E as center and E K as 
radius draw the arc K J representing the seam at the sides. Draw 
the front view in its proper position as F G H, through which 
draw the center line F I representing the seam at back and front, 
thus making the elbow in four pieces. Directly below C B draw 



114 



SHEET METAL WORK 



the section of the elbow as shown by a b c d struck from M as 
center. Through M draw the diameters b d and a c. The inner 
curve of the elbow a d c in plan will be stretched, while the outer 
curve a b c in plan will be raised. Through M draw the diagonal 
3 6 intersecting the circle at 3 and f respectively. JSTow draw 
a d; through/* parallel to a d draw a line intersecting the center 




line A E extended at O. On either side of f place the stretchout 
of 6 a and 6 d as shown by fa' andy d'. Then with radii equal 
to O d' and O a' and with O on the line A B, Fig. 122, as center 
describe the arcs d d and a a. Make the length of d d equal to 
the inner curve D C in Fig. 121. From a and d in Fig. 122 
draw lines to the apex O extending them to meet the outer curve 
at a and a. Then will a d d a he the half pattern for the inner 
portion of the elbow for two sides. The radius for the pattern for 
the outer curve is shown in Fig. 121 by N o, N b\ placing the 



SHEET METAL WORK 



115 



stretchout of the curve on either side of the point e. bbcein Fig. 
122 shows the pattern for the outer curve, the length b b being 
obtained from A B in elevation in Fig. 121. 

In work of this kind the patterns are made a little longer, to 
allow for trimming after the elbow is brazed together. Laps must 
be allowed on all patterns for brazing. 

Fig. 123 shows a perspective view of a brewing kettle, made 
in horizontal sections and riveted. The same principles which 
were employed for obtaining the patterns for a sphere in Fig. 114 
are applicable to this problem. Thus in Fig. 124, let A B C rep- 
resent a full section of a brewing kettle as required according to 
architect's design. Through the middle of the section draw the 
center line D E. Now divide the 
half section B to C into as many parts 
as the kettle is to have pieces as 
shown by c, d, e,f. From these 
small letters draw horizontal lines 
through the section, as shown by 
c A, d d', e e\ and//' and in its 
proper position below the section, 
draw the plan views on each of these 
horizontal lines in elevation, excep- 
ting d' d, as shown respectively by 

IFGH, e" e" and/"/'", all struck from the center a. Now 
through the points c d draw a line which if extended would meet 
the center line. Then this intersection would be the center with 
which to draw the arcs c c and d d"\ the flange c b would be 
added to the pattern as shown by V . The stretchout for this pat- 
tern l 1 would be obtained from the curved line F G H I in plan 
and stepped off on the outer arc c c'. In similar manner through 
d 6, ef y and/ draw the lines intersecting the center line D E 
at K, L, and C. Then using the points as center, describe the 
patterns 2 1 , and 3 1 , and the full circle 4 1 . 

The stretchout for the patterns 2 1 and 3 1 is obtained from the 
circle e" e'" in plan and placed on the inner curve of the pattern 2 1 , 
and on the outer curve of the pattern 3 1 . If desired the stretchout 
could be taken from /"/"' in plan, and placed on the inner eurv« 
of 3 1 which would make the pa ttern similar as before. 




Fig. 123. 



116 



SHEET METAL WORK 



In large kettles of this kind, the length of the pattern is guided 
by the size of the sheets in stock, and if it was desired that each ring 
was to be made in 8 parts then the respective circle in plan from 
which the stretchout is taken would be divided into 8 parts, and 
one of these parts transferred to the patterns, to which laps must 
be allowed for seaming and riveting. 

!D 



FULL SECTION 




Fig. 124. 

PROBLEMS FOR WORKERS IN HEAVY METAL. 

While all of the problems given in this course are applicable to 
developments in heavy metal as well as in that of lighter gauge, the 
following problems relate to those forms made from boiler plate. 

When using metal of heavier gauge than number 20, for pipes, 
elbows, or any other work, it is necessary to have the exact inside 
diameter. It is customary in all shops working the heavier metal, 



SHEET METAL WORK 117 

to add a certain amount to the stretchout to make up for the loss 
incurred in bending, in order that the inside diameter of the article 
(pipe, stack, or boiler shell) may be kept to a uniform and desired 
size. This amount varies according to different practice of work- 
men, some of whom allow 7 times the thickness of the metal used, 
while others add but 3 times the thickness. Theoretically the 
amount is 3.1416 times the thickness of the metal. 

For example, suppose a boiler shell or stack is to be made 48 
inches in diameter out of -J-inch thick metal. If this shell is to 
measure 48 inches on the inside, add the thickness of the metal, 
which is -| inch, making 48-| inches. Multiply this by 3.1416 
and the result will be the width of the sheet. If, on the other 
hand, the outside diameter is to measure 48 inches, subtract the 
thickness of the metal, which would give 47^ inches and multi- 
ply that by 3.1416 which would give the proper width of the sheet. 
It is well to remember that no matter what the thickness of the 
plate may be, if it is not added, the diameter of the finished article 
will not be large enough; for where no account is taken of the 
thickness of the metal, the diameter will measure from the center 
of the thickness of the sheet. "While this rule is theoretically cor- 
rect there is always a certain amount of material lost during the 
forming operations. It is, therefore, considered the best practice to 
use seven times the thickness of the metal in question. The cir- 
cumference for a stack 48 inches in diameter inside using -| inch 
metal would be, on this principle, 3.1416 X 48 -f- (7 X -|) to which 
laps would have to be allowed for riveting. "Where the stack has 
both diameters equal a butt joint is usually employed with a collar 
as shown at either a or h in Fig. 125, but where one end of the stack 
is to fit into the other, a tapering pattern must be obtained which 
will be described as we proceed. 

In putting up large boiler stacks it is usual to finish at the 
top with a moulded cap, and while the method of obtaining the pat- 
terns is similar to parallel line developments, the method of devel- 
oping such a pattern will be given showing how the holes are 
punched for a butt joint. 

In Fig. 126 a view of the moulded cap on a stack is shown. 
On a large size stack the cap is often divided into as many as 32 
pieces. If the stack is to be made in horizontal sections the rules 



118 



SHEET METAL WORK 



given in the problems on coppersniithing apply. While in obtairi- 
ing the patterns for a cap in vertical sections, the plan is usually 
divided into 16 to 32 sides, according to the size of the stack; we 
have shown in Fig. 127 a quarter plan so spaced as to give 8 sides to 
the full circle. This has been done to make each step distinct, the 
lame principles being applied no matter how many sides the plan has. 



I *,, 




Fig. 125. 

First draw the center line A B and with any point as C w T ith 
radius equal to 4| inches draw the quadrant D E. Now tangent to 
D and E, draw the line D F and E G, and at an angle of 45°, tan- 
gent to the curve at Y, draw G F intersecting the previous lines 
drawn at G and F. C D F G E shows the plan view of the extreme 
outline of the cap. Directly above the plan draw a half section of 
the cap, the curve 5 8 being struck from b as center and with a radius 

equal to b 8 or 1| inches. Then us- 
ing the same radius with a as center 
describe the quarter circle 5 2. Make 
2 1 equal to § inch, and 8 9 one inch. 
From the corners F and G in plan 
draw the miter lines F C, C G. 
Divide the profile of the cap into 
equal spaces as shown by the figures 
1 to 9, from which drop vertical 
lines, intersecting the miter line F C 
as shown. On C D extended as C H 
place the stretchout of the profile of 
the cap as shown by similar numbers. 
At right angles to D H draw lines 
as shown, and intersect them by lines drawn parallel to D H from 
the intersections on C F. Trace a line through points thus obtained 
as shown by J I and trace this outline on the opposite side of the 




Fig. 126. 



SHEET METAL WORK 



11& 



line D H as shown by J 1 P. Then will J I P J J be the complete 
pattern for one side. 

When riveting these pieces together an angle is usually placed 
on the inside and the miters butt sharp, filing the corners to make 
a neat fit. This being the case the holes are punched in the pat- 
tern before bending as shown by X X X etc. Assuming that the 




Fig. 127. 



stack on which the cap is to fit is 4.8 inches in diameter, obtain 
the circumference as previously explained and divide by 8 (be- 
cause the plan is composed of 8 pieces) placing one-half of the dis- 
tance on either side of the center line D H in pattern. Assuming 
that ytg of the circumference is equal to 9 e, trace from e the en- 
tire miter cut, as partly shown by e i to the line P I. If the ^ 
circumference were equal to 9 d, the cut would then be traced as 
shown in part by d h until it met the line I V. This, of course, 



SHEET METAL WORK 



would be done on the half pattern 9 J 1 1 before tracing it opposite 
the center line D H. Should the plan be divided into 32 parts, 
divide the circumference of the stack by 32 and place ^- of the cir- 
cumference on 9 J in pattern, measuring from the center line D H, 
and after obtaining the proper cut, trace opposite the line D H. 

In constructing a stack where each joint tapers and fits inside 
of the other, as shown in Fig. 128, a short rule is employed for 
obtaining the taper joints without having recourse to the center. 
In the illustration a b represents the first joint, the second C slip- 



/°f\ 




Fig. 128. 






Fig. 129. 



ping over it with a lap equal toy, the joint being riveted together 
at e and d. When drawing the first taper joint a b, care must be 
taken to have the diameter at f on the outside, equal to the inside 
diameter at the bottom at h. This allows the second joint to slip 
over a certain distance so that when the holes are punched in the 
sheets before rolling, the holes will fit over one another aftsr the 
pipe is rolled. . 

In Fig 129 a b o d is a taper joint drawn on the line of its 
inside diameter, as explained in Fig. 128 f, and e in Fig 129 rep- 
resents respectively the half sections on a b and d c. By the short 
rale the radial lines of the cone are produced without having 



SHEET METAL WORK 



121 



recourse to the apex, which, if obtained in the full-size drawings, 
would be so far away as to render its use impracticable. A method 
similar to the following is used for obtaining the arcs for the pattern 
in all cases where the taper is so slight as to render the use of a 
common apex impracticable. 

Let abed, Fig. 130, be a reproduction of a b c d in Fig. 129. 
On either side of a d and b c, in Fig. 130, place duplicates of 
abed as shown by V c and a' d'. This can be done most accurately 
by using the diagonals d b and c a as radii, and with d and c as 
centers describe the arcs b b' and a a' respectively, and intersect 




Fig. 130, 

them by arcs struck from a and b as centers, with radii equal 
respectively to a b and b a as shown. In precisely the same manner 
obtain the intersection c' and d' at the bottom. Now through the 
intersections b' ab a' and d' c d c' draw the curve as shown by bend- 
ing the straight-edge or any straight strip of wood placed on edge 
and brought against the various intersections, extending the curves 
at the ends and top and bottom indefinitely. Since the circumfer- 
ence of the circle is more than three times the diameter, and as we 
only have three times the diameter as shown from c' to d' and 
b' to a', then multiply .1416 times the bottom and top diameter d c 
and a b respectively, and place one-half of the amount on either side 
of the bottom and top curves as shown by <?, e', and A, h'. Now take 
one-half of seven times the thickness of the metal in use and place 



122 SHEET METAL WORK 

it on either side on the bottom and top curves as shown by f,f and 
if i\ and draw a line from i tof and i' tof. To this lap must be 
allowed for riveting. The desired pattern is shown by i i' f ' f. 

Fig. 131 shows a three-pieced elbow made from heavy metal, 
the two end pieces fitting into the center pieces, to which laps are 
allowed for riveting. The principles which shall be explained to 
cut these patterns and make the necessary allowance for any thick- 
ness of metal is applicable to any elbow. 

In Fig. 132 draw as previously described the elbow ABC, 
below G H draw the section of the inside diameter as D which is 
struck from a, and divide into equal spaces as shown by the figures 
1 to 5 on both sides. Through these figures draw vertical lines 

intersecting the miter line b c, and from 
these intersections parallel to c d draw 
lines intersecting the line ieas shown. 
Before obtaining the stretchout for 
these elbows, a preliminary drawing 
must be constructed, in which an allow- 
ance is made for the thickness of the 
material that is to be used. This draw- 
ing makes practical use of a principle 
„. .„, well known to draughtsmen from its 

application to the proportional division 
of lines and is clearly shown at (R). In allowing for the thick- 
ness of the metal in use, it is evident that we cannot allow it at one 
end, but must distribute it uniformly throughout the pattern. In 
(R) draw any horizontal line as E F, upon which place the stretch- 
out of the inside diameter of the pipe D, as shown by similar 
figures on E F. From 1° on E F lay off the distance 1° m equal 
to 7 times the thickness of the metal in use as before explained. 
Then using E as center and Emas radius, draw the arc m 1' inter- 
secting the vertical line drawn from 1°, and from the various 
intersections from 1 to 1° on E F erect perpendiculars intersecting 
the slant line 1 1' at 2' 3' 4', etc., as shown. The slant line 1 1, 
with the various intersections is now the correct stretchout for the 
elbow made of such heavy material called for by the specifications. 
On G H extended, as H I, place the stretchout of the slant line 
1 1' as shown from 1 to V on H I. At right angles to H I and 




SHEET METAL WORK 



123 



from the various intersections, erect lines, which are intersected 
by lines drawn parallel to II I from similar numbered intersec- 
tions on the miter line b c. Trace the curve LI. LMIH shows 
the pattern for the two end pieces of the elbow. 

As the middle section A in Fig. 131 is to overlap the two end 
pieces, it is unnecessary to allow for any additional thickness on 




rmn' 



account of this lap when suitable flanging machines are available; 
but since it is desirable, in some instances, to make an allowance 
in the pattern for riveting, the method of allowing for this lap 
will be explained. 

In (R), Fig. 132, lay off on the line E F the distance m n 
equal to 7 times the thickness of the metal in use, and with radius 
equal to E n draw an arc intersecting the line 1° 1' extended at 1". 
Draw the slant line from 1" to 1 and extend all the vertical lines 
to intersect 1 1" at 2" 3" 4", etc. The slant line 1 1" js the cor- 



124 



SHEET METAL WORK 



rect stretchout for the middle section B. At right ano-les to d c 
draw J K equal to 1 5" 1" in (R), as shown by similar figures in 
J K, through which draw lines at right angles to J K, and inter- 
sect them by lines drawn at right angles to d c as shown. Trace 
the curved lines to produce OPES, which is the pattern for the 

middle section, to which flanges are al- 
lowed as shown by dotted lines. 

The perspective of an intersection 
between pipes having different diam- 
eters in boiler work is shown in Fig. 
133. "While the method of obtaining 
the patterns is similar in principle to 
parallel line developments, a slight 
change is required in obtaining the 
allowance in the stretchout for the thickness of the metal in use. 
Let A B, Fig. 134, represent the part section of a boiler struck 
with a radius equal to 3|" and let 1 7 7° 1° be the elevation of the 
intersecting pipe, whose inside diameter is 4|", as shown by 1 7. 

2/ INSIDE > 6 

'jgAMgre^ , g 3 , , 5 , 6 , 7 , fi , g A , t 

I TT —1 1 ■ 





a"^> E 1 1 h 

p— ^1 II III r 

i°2° 3° 4 5 ^7°e *" 
Fig. 134. 

Divide the half section 1 4 7 into an equal number of spaces, as 
numbered, from which drop vertical lines intersecting the outside 
line of the boiler at 1° to 7° as shown. A true stretchout must now 
be obtained in which allowance has been made for the thickness 
of the metal in use. Therefore, in Fig. 135, on the horizontal 
line A B lay off the stretchout of twice the inside section of 



SHEET METAL WORK 125 

the pipe in Fig. 134, as shown by similar figures on A B in Fig. 
135, adding l x «, equal to 7 times the thickness of the metal in 
use. For example, supposing ^-inch steel was used; the distance 
l x a would then be equal to 7 X ^, or 1| inches. Now draw the arc 
a 1', using 1 as center, which is intersected by the vertical line drawn 
from l x . From 1' draw a line to 1, and from the various points 
on A B erect perpendiculars intersecting 1 1' at 2' 3' 4', etc. 1 1' 
shows the true stretchout to be be laid off on the line 1 7 extended 
in Fig. 134 as 1 1', and from the various intersections on 1 1' drop 
vertical lines and intersect them bylines drawn parallel to 1 1' from 
similar intersections on the curve 1° 7° as shown. Trace a curved 
line as shown from C to D. 1 C D 1' shows the pattern for the 
vertical pipe to which a flange must be allowed for riveting as 
shown by the dotted line. 

It is now necessary to obtain the pattern for the shape to be 
cut out of the boiler sheet, to admit the mitering of the vertical 
pipe. In some shops the pattern is not developed, only the vertical 
pipe is flanged, as shown in Fig. 133, then set in its proper posi- 
tion on the boiler and line marked along the inside diameter of the 
pipe, the pipe is then removed and the opening cut into the boiler 
with a chisel. We give, however, the geometrical rule for obtain- 
ing the pattern, and either method can be used. 

As A B in Fig. 134 represents the outside diameter of the 
boiler, to which 7 times the thickness of the metal used must be 
added to the circumference in laying out the sheet, and as the ver- 
tical pipe intersects one-quarter of the section as shown by a b c, 
take the stretchout from 1° to 7° and place it from 1° to 7° on 
F G in (E), to which add 7° e, equal to ^ of 7 times the thick- 
ness of the plate used. Draw the arc e 7", using 1° as center, 
intersecting it by the vertical line drawn from 7°. Erect the usual 
vertical lines and draw 7" 1°, which is the desired stretchout. Now 
place this stretchout on the line A B in Fig. 136, erecting vertical 
lines as shown. Measuring in each and every instance from the 
line 1 7 in Fig. 134, take the various distances to points 2, 3, 4, 5, 
and 6 and place them in Fig. 136 on lines having similar numbers, 
measuring in each instance from A B on either side, thus obtain- 
ing the points 2, 3. 4, 5, and 6. Trace the curve 1° 4 7" 4, which 
is the desired shape. 



126 



SHEET METAL WOKK 



Fig. 137 shows a perspective of a gusset sheet A on a loco- 
motive, the method of obtaining this pattern in heavy metal is 
shown in Fig. 138. First draw the end view ABO, the semi- 
circle 4 14 being struck from a as center with a radius equal to 2 




inches. Make the distance 4 to C and 4 to B both 3| inches and 
draw C B. Draw the center line A F, on which line measure up 
2^ inches and obtain h, which use as center with radius equal to a 
4, draw the section of the boiler D E F G. In its proper position 
draw the side view HIJKLMK HILMNH shows the 
side view of the gusset sheet shown in 6nd view by G A E D G. 
Divide the semicircle 4 1 4 in end view into equal spaces as 
shown, from which draw horizontal lines intersecting HNin side 





Fig. 136. 



Fig. 137. 



view from 1' to 4'. From these intersections parallel to H I, 
draw lines indefinitely intersecting I L from 1" to 4". At right 
angles to N L produced draw the line at c d, on which a true 
section must be obtained at right angles to the line of the gusset 
sheet. Measuring from the line A D in end view, take the vari- 
ous distances to points 2, 3, and 4 and place them on correspond- 
ing lines measuring from the line c d on either side, thus obtaining 



SHEET METAL WORK 



127 



the intersections 1° to 4°, a line traced through these points will 
be the true section. In (Y) on any line as O P lay off the stretch- 
out of the true section as shown from 4°, 1°, 4°. As the gusset 
sheet only covers a portion equal to a half circle, add the distance 
4° e equal to ^ of 7 times the thickness of the metal in use and 




Fig. 138. 

using 4° at the left, as center with 4° e as radius, describe the arc 
e 4 X , intersecting it at 4 X by the vertical line drawn from 4°. From 
P erect vertical lines intersecting the line drawn from 4 X to 4° 
at 3 X , 2 X , l x , etc. 4° 4 X is the true stretchout, and should be 
placed on the line K S drawn at right angles to H I. Through 
the numbers on B 8 and at right angles draw the lines shown 
and intersect them by lines drawn from similarly numbered inter- 
sections on II N and I L at right angles to H I. Through points 



128 SHEET METAL WOEK , 

thus obtained trace a curved line 4 s , 4 s , and 4 V , 4 V . It now be- 
comes necessary to add the triangular piece shown by L M N in 
side view, to the pattern which can be done as follows: Using L M 
in side view as radius and 4 V at either end of the pattern as cen- 
ters, describe the arcs m and n\ intersect them by arcs struck from 
4 s and 4 s as centers, and M N in side view as radius. Then draw 
lines from 4 s to m to 4 V in the pattern on either side. The full pat- 
tern shape for the gusset sheet will then be shown by m 4 s 4 s m 
4 V 4 V , to which laps must be allowed for riveting. 

Fig. 139 shows a conical piece connecting two boilers with 
the flare of A such that the radial lines can be used in developing 
the pattern. In all such cases this method should be used in pref- 
erence to that given in connection with Fig. 130. Thus in Fig. 
139 the centers of the two boilers are on one line as shown by a b. 
While the pattern is developed the same as in flaring work, the 
method of allowing for the metal used is shown in Fig. 140. 

A B C D is the elevation 

( 'd ^^aBEgg^^ r of the conical piece, the half 

inside section being shown 
by 1 4 7 which is divided 

EJI7 fg^ jjpMI^^^^ i i n t e q Ua i spaces. 1 7 1 in 

Fig. 139. (E) is the full stretchout of 

the inside section A 4 D in 
elevation, and 1 e is equal to 7 times the thickness of the metal 
used. The line 1 1' is then obtained in the usual manner as are 
the various intersections 2' 3' 4', etc. Now extend the lines A B 
and D C in elevation until they meet the center line a b at a. 
Then using a c and a d draw the arcs 1' 7' and 1" 7". From 1' 
draw a radial line to a, intersecting the inner arc at 1". Now set 
the dividers equal to the spaces on 1 1' in (E) and starting from 1' 
in the pattern step off 6 spaces and draw a line from 7' to a inter- 
secting the inner arc at 7". 1' 7' 1" 7" shows the half pattern to 
which flanges must be allowed for riveting. 

Fig. 141 shows a view of a scroll sign, generally made of 
heavy steel, heavy copper, or heavy brass. So far as the sign is 
concerned it is simply a matter of designing, but what shall be 
given attention here is the manner of obtaining the pattern and 
elevation of the scroll. As these scrolls are usually rolled up in 



-to 



SHEET METAL WORK 



129 



form of a spiral, the method of drawing the spiral will first 
be shown. 

Establish a center poin^ as a' in Fig. 142, and with the desired 
radius describe the circle shown, which divide into a polygon of 




Fig. 140. 

any number of sides, in this case being 6 sides or a hexagon. 
The more sides the polygon has, the nearer to a true spiral will 
the figure be. Therefore number the corners of the hexagon 1 to 





WORK 
AND PLUMBING. 




Fig. 141. 



5 and draw out each side indefinitely as 1 a, 2 3, 3 c, 4 d y 5 6, and 
Qf. Now using 2 as center and 2 1 as radius, describe the arc 
1 A; then using 3 as center and 3 A as radius, describe the arc 



180 SHEET METAL WOKK 

A B, and proceed in similar manner using as radii 4 B, 5 C, 6 D. 
and 1 E, until the part of the spiral shown has been drawn. Then 
using the same centers as before continue until the desired spiral is 
obtained, the following curves running parallel to those first drawn. 
The size of the polygon a', determines the size of the spiral. 

In Fig. 143 let A B C D represent the elevation of one corner 
of the flag sign shown in Fig. 141. In its proper position in Fig. 
143 draw a section of the scroll through its center line in elevation 
as shown by a 17 to 1, which divide into equal spaces as shown 
from 1 to 17. Supposing the scroll is to be made of ^ inch thick 



Fig. 142. 

metal, and as the spiral makes two revolutions then multiply ^ 
by 14, which would equal 1| inches. Then on E F in Fig 144 
place the stretchout of the spiral in Fig. 143, as shown by similar 
numbers, to which add 17 E equal to 14 times the thickness of 
metal in use, and draw the arc E 17' in the usual manner and 
obtain the true stretchout with the various intersections as shown. 
Through the elevation of the corner scroll in Fig. 143 draw the 
center line E F, upon which place the stretchout of 17' E, Fig. 
144, as shown by similar numbers on E F in Fig. 143. At right 
angles toE F, through 1'and 17', draw 17° 17° equal to AB and 1° 1° 
equal to the desired width of the scroll at that point. Then at 
pleasure draw the curve 1° 17° on either side, using the straight- 



SHEET METAL WORK 



1S1 




Pig. 143. 



132 SHEET METAL WORK 

edge and bending it as required. Then will 1° 1° 17° 17° be the 
pattern for the scroll using heavy metal. 

If it is desired to know how this scroll will look when rolled 
up, then at right angles to E F and through the intersections 1' to 
17' draw lines intersecting the curves of the pattern 1°-17° on 
both sides. From these intersections, shown on one side only, 
drop lines intersecting similar numbered lines, drawn from the 
intersections in the profile of the scroll in section parallel to A B. 
To avoid a confusion of lines the points l x , 3 X , 5 X , 7 X , 10 x , 12 x , 
and 17 x have only been intersected. A line traced through points 
thus obtained as shown from l x to 17 x in elevation gives the pro- 
jections at the ends of the scroll when rolled up. 



SKYLIGHT WORK* 



The upper illustration shows the layout of a fiat pitched skylight whose 
curb measures 6' — 0"X7' — 6", the run of the rafter or length of the glass being 
6' 0" on a horizontal line. Five bars are required, making the glass 15 inches 
wide A working section through AB and CD is shown below. 

It will be noticed in the section through AB that the flashing is locked to 
the roofing and flanged around the inside of the angle iron construction; over 
this the curb of the skylight rests, bolted through the angle iron as shown, the 
bolt being capped and soldered to avoid leakage. 

The same construction is used in the section through CD, with the excep* 
tion, that when the flashing cannot be made in one piece, a cross lock is placed 
in the manner indicated, over the fireproof blocks. 



* The illustration referred to will be found on the back of this puge. 



conaTDucTiori Dx^Awma anowina layout 

OF FLAT SKYLIGHT AHD i^TJ-iOD OF 
FA5TE.ftI.riG FLASRIttG On A?iGLE 

ir,oK consTMJCTion. 




Conde n-saJ ton 
#ub© 



~-ROOf tt«°' 



Section throuo.h low«.r 
end. of curb A.-B 



upper end of curb 

c-r> 



FOR EXPLANATION OF THIS PROBLEM SEE BACK OF PAGE 



SHEET METAL WORK 

PART III 



SKYLIGHT WORK 

Where formerly skylights were constructed from wrought iron 
or wood, to-day in all the large cities they are being made of galvanized 
sheet iron and copper. Sheet metal skylights, having by their peculiar 
construction lightness and strength, are superior to iron and wooden 
lights; superior to iron lights, inasmuch as there is hardly any expan- 
sion or contraction of the metal to cause leaks or breakage of glass; and 
superior to wooden lights, because they are fire, water and condensa- 
tion^ proof , and being less clumsy, admit more light. 

The small body of metal used in the construction of the bar and 
curb and the provisions which can be made to carry off the inside con- 
densation, make sheet metal skylights superior to all others constructed 
from different material. 

CONSTRUCTION 

The construction of a sheet metal skylight is a very simple matter, 
if the patterns for the various 
intersections are properly devel- 
oped. For example, the bar 
shown in Fig. 145 consists of a 
piece of sheet metal having the 
required stretchout and length, 
and bent by special machinery, 
or on the regular cornice brake, 
into the shape shown, which rep- 
resents strength and rigidity with 
the least amount of weight. A A 
represent the condensation gut- 
ters to receive the condensation 




Fig. 145. 




from the inside when the warm air strikes against the cold surface of 
the glass, while B B show the rabbets or glass-rest for the glass. 

In Fig. 146, C C is a re-enforcing strip, which is used to hold the 



134 



SHEET METAL WORK 




two walls O O together and impart to it great rigidity. When skylight 

bars are required to bridge long spans, an internal core is made of 

sheet metal and placed as shown at A in Fig. 147, which adds to its 

weight-sustaining power. In this figure B B shows the glass laid on 

a bed of putty with the metal cap 
C C C, resting snugly against the 
glass, fastened in position by the 
rivet or bolt D D. Where a very 
large span is to be bridged a bar 
similar to that shown in Fig. 148 is 
used. A heavy core plate A made 
of |-inch thick metal is used, riveted 
or bolted to the bar at B and B. In 
construction, all the various bars 
terminate at the curb shown at A B 
C in Fig. 149, which is fastened to 
Fi S- 147 - the wooden frame D E. 

The condensation gutters C C in the bar b, carry the water into 

the internal gutter in the curb at a, thence to the outside through holes 

provided for this purpose at F F. In Fig. 150 is shown a sectional 

view of the construction of a double-pitched 

skylight. A shows the ridge bar with a core in 

the center and cap attached over the glass. B 

shows the cross bar or clip which is used in 

large skylights where it is impossible to get the 

glass in one length, and where the glass must 

be protected and leakage prevented by means 

of the cross bar, the gutter of which conducts 

the water into the gutter of the main bar, 

thence outside the curb as before explained. 

C is the frame generally made of wood or angle 

iron and covered by the metal roofer with flash- 
ing as shown at F. D shows the skylight bar 

with core showing the glass and cap in position. 




M!^ 



Fig. 148. 

E is the metal curb 
against which the bars terminate, the condensation being let out 
through the holes shown. 

In constructing pitched skylights having double pitch, or being 
hipped, the pitch is usually one-third. In other words it is one-third 



SHEET METAL WORK 



135 



of the span.. If a skylight were 12 feet wide and one-third pitch were 
required, the rise in the center would be one-third of 12, or 4 feet. 
When a flat skylight is made the 
pitch is usually built in the wood 
or iron frame and a flat skylight 
laid over it. The glass used in 
the construction of metallic sky- 
lights is usually f-inch rough or 
ribbed glass; but in some cases 
heavier glass is used. 

If for any reason it is desired 
to know the weight of the various 
thickness of glass, the following 
table will prove valuable. 

Weight of Rough Glass Per 
Square Foot. 

Thickness in inches. 

4-314443 i 

¥• TV* 4' £• 2> f* 4- 1 - 

Weight in pounds. 

2. 2£. 3J. 5. 7. 8£. 10. 12£. 




Fig. 149 




Fig. 150. 



136 



SHEET METAL WORK 



SHOP TOOLS 

In the smaller shops the bars are cut with the hand shears and 
formed up on the ordinary cornice brake. In the larger shops, the 
strips required for the bars or curbs are cut on the large squaring 
shears, and the miters on the ends of these strips are cut on what is 
known as a miter cutter. This machine consists of eight foot presses 
on a single table, each press having a different set of dies for the purpose 
of cutting the various miters on the various bars. The bars are then 
formed on what is known as a Drop Press in which the baT can be 
formed in two operations to the length of 10 feet. 

METHOD EMPLOYED IN OBTAINING THE PATTERNS 
The method to be employed in developing the patterns for the 
various skylights is by parallel lines. If, however, a dome, conserva- 
tory or circular skylight is required, the blanks for the various curbs, 
bars, and ventilators are laid out by the rule given in the dis- 
cussion of circular mouldings beginning on page 249. 

VARIOUS SHAPES OF BARS 

In addition to the shapes of bars shown in Figs. 145 to 148 in- 
clusive, there is shown in Fig. 151 a plain bar without any condensation 
gutters, the joint being at A. B B represents the glass resting on the 
rabbets of the bar, while C shows another form of cap which covers 




ES^M H^M 





B — 



Fig. 152. Fig. 153. 

the joint between the bar and glass. Fig. 152 gives another form of 
bar in which the condensation gutters and bar are formed from one 
piece of metal with a locked hidden seam at A. Fig. 153 shows a bar 
on which no putty is required when glazing. It will be noticed that 
it is bent from one piece of metal with the seam at A, the glass B B 
resting on the combination rabbets and gutters C C. D is the cap 
which is fastened by means of the cleat E. These cleats are cut about 
£-inch wide from soft 14-oz. copper, and riveted to the top of the bar 



SHEET METAL WORK 



137 



at F; then a slot is cut into the cap D as shown from a to b in Fig. 154; 
then the cap is pressed firmly onto the glass and the cleat E turned 
down which holds the cap in position. 

When a skylight is constructed in which raising sashes are re- 
quired, as shown in Fig. 155, half bars are required at the sides A and 
B, while the bars on each side of the sash to be 
raised are so constructed that a water-tight joint 
is obtained when closed. This is shown in Fig. 
156, which is an enlarged section through A B in 
Fig. 155. Thus in Fig. 156, A A represents the 
two half bars with condensation gutters as shown, 
the locked seam taking place at B B. C C repre- 
sent the two half bars for the raising sash with the caps D D attach- 
ed to same, as shown, so that when the sash C C is closed, the caps 




Fig. 154. 




Fig. 155. 
D D cover the joint between the glass E E and the stationary half 
bars. F F are the half caps soldered at a a to the bars C C which 
protect the joints between the glass H H and the bars C C. 

VARIOUS SHAPES OF CURBS 



1° IE 




In Figs. 157, 158 and 159 
are shown a few shapes of curbs 
which are used in connection 
with flat skylights. A in Fig. 
157 shows the curb for the three 
sides of a flat skylight, formed in 
one piece with a joint at B, while 
C shows the cap, fastened as previously described. "A" shows the 
height at the lower end of the curb, which is made as high as the 
glass is thick and allows the water to run over. In Fig. 158, A is 



138 



SHEET METAL WORK 



another form of skylight formed in one piece and riveted at B; 
a shows the height at the lower end. In the previous figures the frame 
on which the metal curb rests is of wood, while in Fig. 159 the frame is 






Fig. 157. Fig. 158. 



Fig. 159. 



of angle iron shown at A. In this case the curb is slightly changed 
as shown at B ; bent in one piece, and riveted at C. In Figs. 160, 161, 
and 162 are shown various shapes of curbs for pitched skylights in 
addition to that shown in Fig. 149. A in Fig. 160 shows a curb formed 
in one piece from a to 6 with a condensation hole or tube shown at B. 




Fig. 160. Fig. 161. Fig. 162. 

In Fig. 161 is shown a slightly modified shape A, with an offset to 
rest on the curb at B. When a skylight is to be placed over an opening 
whose walls are brick, a gutter is usually placed around the wall, as 



SHEET METAL WORK 



139 



shown in Fig. 162, in which A represents a section of the wall on which 
a gutter, B, is hung, formed from one piece of metal, as shown from a 
to b to c. On top of this the metal curb C is soldered, which is also 
formed from one piece with a lock seam at i. To stiffen this curb a 
wooden core is slipped inside as shown at D. From the inside con- 
densation gutter / a 14-oz. copper tube runs through the curb, shown 
at d. The condensation from the gutter e in the bar, drips into the 
gutter /, out of the tube d, into the main gutter B, from which it is con- 
veyed to the outside by a leader. 

In Fig. 163 is shown an enlarged section of a raising sash, taken 
through C D in Fig. 155. A in Fig. 163 shows the ridge bar, B the 
lower curb and C D the side sections of the bars explained in connec- 
tion with Fig. 156. E F in h 
Fig. 163 shows the upper I 
frame of the raising sash, fit- 
ting onto the half ridge bar 
A. On each raising sash, at 
the upper end two hinges H 
are riveted at E and I, which 
allow the sash to raise or close 
by means of a cord, rod, or 
gearings. J K shows the 
lower frame of the sash fitting 
over the curb B. Holes are 
punched at a to allow the 
condensation to escape into b, 
thence to the outside through Fig. 163. 
C. Over the hinge H a hood or cap is placed which prevents 
leakage. Fig. 164 shows a section through A B in Fig. 167 and rep- 
resents a hipped skylight having one-third pitch. By a skylight of 
one-third pitch is meant a skylight whose altitude or height A B, is equal 
to one-third of the span C D. If the skylight was to have a pitch of 
one-fourth or one-fifth, then the altitude A B would equal one-fourth 
or one-fifth respectively of the span C D. 

The illustration shows the construction of a hipped skylight with 
ridge ventilator which will be briefly described. C D is the curb; E E 
the inside ventilator; F F the outside ventilator forming a cap over the 




140 



SHEET METAL WORK 



glass at a. G shows the hood held in position by two cross braces H. 
J represents a section of the common bar on the rabbets of which the 
glass K K rests. L shows the condensation gutters on the bar J, 




Fig. 164. 



which are notched out as shown at M, thus allowing the drip to enter 
the gutter N and discharge through the tube P. The foul air escapes 
under the hood G as shown by the arrow. 




SHEET METAL WORK 



141 



VARIOUS STYLES OF SKYLIGHTS 

In Fig. 165 is shown what is known as a single-pitch light, and is 
placed on a curb made by the carpenter which has the desired pitch. 




Fig. 166. 

These skylights are chiefly used on steep roofs as shown in the illus- 
tration, and made to set on a wooden curbs pitching the same as the 




Fig. 167. 

roof, the curb first being flashed. Ventilation is obtained by raising 
one or more lights by means of gearings, as shown in Fig. 155. 




Mg. i6S. 



142 



SHEET METAL WORK 



Fig. 166 shows a double-pitch skylight. Ventilation is obtained 
by placing louvres at each end as shown at A. Fig. 167 shows a 
skylight with a ridge ventilator. The corner bar C is called the hip 
bar; the small bar D, inhering against the corner bar, is called the jack 
bar, while E is called the common bar. Fig. 168 illustrates a hip mon- 
itor skylight with glazed opening sashes for ventilation. These sashes 
can be opened or closed separately, by means of gearings similar to 
those shown in Fig. 177 In Fig. 169 is shown the method of raising 




sashes in conservatories, greenhouses, etc., the same apparatus being 
applicable to both metal and wooden sashes. Fig. 170 shows a view 
of a photographer's skylight ; if desired, the vertical sashes can be made 
to open. 

In Fig. 171 is shown a flat extension skylight at the rear of a store 
or building. The upper side and ends are flashed into the brick work 
and made water-tight with waterproof cement, while the lower side 
rests on the real wall to which it is fastened. In some cases the rear 



SHEET METAL WORK 



143 



gutter is of cast iron, put up by the iron worker, but it is usually made 
of No. 22 galvanized iron, or 20-oz. cold-rolled copper. To receive 
the bottom of the gutter and skylight, the wall should be covered by a 
wooden plate A, Fig. 172, about two inches thick, and another plank 
set edgeways flush with the inside of the wall, as shown at B. The 
two planks are not required when a cast iron gutter is used. 

Fig. 173 shows a hipped skylight without a ridge ventilator, set 
on a metal curb in which louvres have been placed. These louvres 
may be made stationary or movable. When made movable, they are 




Fig. 170. 

constructed as shown in Fig. 174, in which A shows a perspective view, 
B shows them closed, and C open. They are operated by the quad- 
rants attached to the upright bars a and b, which in turn are pulled up 
and down by cords or chains worked from below. WTien a skylight 
has a very long span, as in Fig. 175, it is constructed as shown in Fig. 
176, in which A represents a T-beam which can be trussed if necessary. 
This construction allows the water to escape from the bottom of the 
upper light to the outside of the top of the lower skylight, the curb C 
of the upper light fitting over the curb 6 of the lower light. 



144 



SHEET METAL WORK 



In Fig. 177 is shown the method of applying the gearings. A 
shows the side view of the metal or wooden sash partly opened, B the 




Fig. 171. 

end of the main shaft, and C the binder that fastens the main shaft k> 
the upright or rafter. D shows the quadrant wheel attached to main 
shaft and E is the worm wheel, geared to the quadrant D, commun- 
icating motion to the whole shaft. 
F is a hinged arm fastened to the 
main shaft B and hinged to the 
sash. By turning the hand-whee 1 
the sash can be opened at any 
angle. 

DEVELOPMENT OF PATTERNS 
FOR A HIPPED SKYLIGHT 

The following illustrations 
and text will explain the princi- 
ples involved in developing the 
patterns for the ventilator, curb, 
hip bar, common bar, jack bar, 
and cross bar or clip, in a 
hipped skylight. These princi- 




Hg. 172. 



pies are also applicable to any other form of light, whether flat, 
double-pitch, single-pitch, etc. 



SHEET METAL WORK 



14ft 



In Fig. 178 is shown a half section, a quarter plan, and a 
diagonal elevation of a hip bar, including the patterns for the curb, 
hip, jack, and common bars. The method of making these drawings 
will be explained in detail, so that the student who pays close attention 




Fig. 173 

will have no difficulty in laying out any patterns no matter what the 
pitch of the skylight may be, or what angle its plan may have. 

First draw any center line as A B, at right angles to which lay off 
C 4', equal to 12 inches. Assuming that the light is to have one-third 






Fig. 174. 

pitch, then make the distance C D equal to 8 inches which is one-third 
of 24 inches, and draw the slant line D 4/ At right angles to D 4' place 
a section of the common bar as shown by E, through which draw lines 
parallel to D 4', intersecting the curb shown from a to / at the bottom 
and the inside section of the ventilator from F to G at the top. At 



146 



SHEET METAL WORK 



pleasure draw the section of the outside vent shown from h to I and the. 
hood shown from m to p. X represents the section of the brace resting 
on i j to uphold the hood resting on it in the corner o. The condensa- 




Fig. 175. 
tion gutters of the common bar E are cut out at the bottom at 5' 6' 
which allows the drip to go into the gutter d e f of the curb and pass 
out of the opening indicated by the arrow. Number the corners of 
each half of the common bar section E as shown, from 1 to 6 on each 

side, through which draw lines 
parallel to D 4' until they inter- 
sect the curb at the bottom as 
shown by similar numbers 1' to 
6', and the inside ventilator at the 
top by similar figures 1" to 6". 
This completes the one half-sec- 
tion of the skylight. From this 
section the pattern for the com- 
mon bar can be obtained without 
the plan, as follows: 
At right angles to D 4' draw the line I J upon which place the 
stretchout of the section E as shown by similar figures on I J. Through 
these small figures, and at right angles to I J, draw lines, and intersect 
them by lines drawn at right angles to D 4' from similarly numbered 
intersections Y to 6' on the curb and 1" to 6" on the inside ventilator. 
Trace a line through points thus obtained ; then A 1 B 1 C l D* will be the 




Fig. 176. 



SHEET METAL WORK 



147 



pattern for the common bar in a hipped skylight. The same method 
would be employed if a pattern were developed for a flat or a double- 
pitch light. From this same half section the pattern for the curb is 
developed by taking the stretchout of the various corners in the curb, 
a b 3' 4' c d e and /, and placing them on the center line A B as shown 
by similar letters and figures. Through these divisions and at right 
angles to A B draw lines which intersect with lines drawn at right 
angles to C 4' from similar points in the curb section a f. Trace a line 
through points thus obtained ; then E 1 F 1 / a will be the half pattern for 
the curb shown in the half section. V represents the condensation hole 
to be punched into the pattern between each light of glass in the sky- 
light. As the portion c d turns up on c 4', use r as a center, and with 




Fig. 177. 

the radius r s strike the semicircle shown. Above this semicircle 
punch the hole V. 

Before the patterns can be obtained for the hip and jack bars, a 
quarter plan view must be constructed which will give the points of 
intersections between the hip bar and curb, between the hip bar and 
vent, or ridge bar, and between the hip and jack bar. Therefore, from 
any point on the center line A B as K, draw K L at right angles to A B. 
As the skylight forms a right angle in plan, draw from K, at an angle 
of 45°, the hip or diagonal line K 1°. Take a tracing of the common 
bar section E with the various figures on same, and place it on the hip 
line K 1° in plan so that the points 1 4 come directly on the hip as 
shown by E 1 . Through the various figures draw lines parallel to K 1° 



WSTTCRN FOR 

CCMMOW BAR 



FOR UPPER £jN9 
OF JACK BAR 




Fig. 178. 



SHEET METAL WORK 149 

one-half of which are intersected by vertical lines drawn parallel to A 
B from similar points of intersection 1' to 6' on the curb, and 1" to 6" 
on the ventilator in the half section, as shown respectively in plan by 
intersections 1° to 6° and l v to 6 V . Below the hip line K 1° trace the 
opposite intersection as shown. It should be understood that the 
section E 1 in plan does not indicate the true profile of the hip bar 
(whichmust be obtained later), but is only placed there to give the hori- 
zontal distances in plan. In laying out the work in practice to full size, 
the upper half intersection of the hip bar in plan is all that is required. 
It will be noticed that the points of intersections in plan and one half 
section have similar numbers, and if the student will carefully follow 
each point the method of these projections will become apparent. 

Having obtained the true points of intersections in plan the next 
step is to obtain a diagonal elevation of the hip bar, from which a true 
section of the hip bar and pattern are obtained. To do this draw any 
line as R M parallel to K 1°. This base line R M has the same eleva- 
tion as the base line C 4' has in the half section. From the various 
points 1° to 6° and l v to 6 V in plan, erect lines at right angles to K 1° 
crossing the line R M indefinitely. Now measuring in each and every 
instance from the line C 4' in the half section take the various distances 
to points D 1" 2" 3" 4" 5" and 6" at the top, and to points 1' 2' 3' 4' 5' 
and 6' at the bottom, and place them in the diagonal elevation meas- 
uring in each and every instance from the line R M on the similarly 
numbered lines drawn from the plan, thus locating respectively the 
points N 1 T 2 T 3 T 4 T 5 T and 6 T at the top, and l p 2 P 3 P 4 P 5 P and 6 P at 
the bottom. Through the points thus obtained draw the miter lines 
1 T to 6 T and l p to 6 P and connect the various points by lines as shown, 
which completes the diagonal elevation of the hip bar intersecting the 
curb and vent, or ridge. To obtain the true section of the hip bar, 
take a tracing of the common bar E or E 1 and place it in the position 
shown by E 3 , being careful to place the points 1 4 at right angles to 
1 T l p as shown. From the various points in the section E 3 at right 
angles to l p 1 T draw lines intersecting similarly numbered lines in the 
diagonal elevation as shown from 1 to 6 on either side. Connect these 
points as shown ; then E 4 will be the true profile of the hip bar. Note 
the difference in the two profiles; the normal E 3 and the modified E 4 . 

Having obtained the true profile E 4 the pattern for the hip bar is 
obtained by drawing the stretchout line O P at right angles 1 T l p . 



150 SHEET METAL WORK 

Take the stretchout of the profile E 4 and place it on O P as shown by 
similar figures. Through these small figures and at right angles to 
O P draw lines which intersect by lines drawn at right angles to 1 T l p 
from similarly numbered points at top and bottom, thus obtaining the 
points of intersections shown. A line traced through the points thus 
obtained, as shown by H 1 J 1 K 1 L 1 will be the pattern for the hip bar. 

For the pattern for the jack bar, take a tracing of the section of the 
common bar E and place it in the position in plan as shown by E 2 
being careful to have the points 1 and 4 at right angles to the line l x 1°. 
It is immaterial how far the section E 2 is placed from the corner 2° as 
the intersection with the hip bar remains the same no matter how far 
the section is placed one way or the other. Through the various 
corners in the section E 2 draw lines at right angles to the line 1° l x inter- 
secting one half of the hip bar on similarly numbered lines as shown by 
the intersections l L 2 L 3 Ij 4 L 5 L 6 L and 1 L 2 J S 3 J 4 L 5 J and6 J ; also inter- 
secting the curb in plan at points l x to 6 X . The intersection between 
the jack bar and curb in plan is not necessary in the development of 
the pattern as the lower cut in the pattern for the common bar is the 
same as the lower cut in the pattern for the jack bar. However, the 
intersection is shown in plan to make a complete drawing. At right 
angles to the line of the jack bar in plan, and from the various inter- 
sections with the hip bar, erect lines intersecting similarly numbered 
lines in the section as shown. Thus from the various intersec- 
tions shown from 1 L to 6 L in plan, erect vertical lines intersect- 
ing the bar in the half section at points shown from 1 L to 6 L . In 
similar manner from the various points of intersections 3 J , 5 J , and 6 J 
in plan, erect lines intersecting the bar in the half section at points 
shown by 3 J 5 J 6 J . Connect these points in the half section, as shown, 
which represents the line of joint in the section between the hip and jack 
bars. 

For the pattern for the upper cut of the jack bar, the same stretch- 
out can be used as that used for the common bar. Therefore, at right 
angles to D 4' and from the various intersections 1 L 2 L 3 L 4 L 5 L and 6 L 
draw lines intersecting similar numbered lines in the pattern for the 
common bar as shown by similar figures. In similar manner from the 
various intersections 3 J 5 J and 6 J in the one half section, draw lines at 
right angles to D 4' intersecting similarly numbered lines in the pattern 
as shown by 3 J 5 J and 6 J . Trace lines from point to point, then the 



SHEET METAL WORK 



151 



cut shown from N 1 to P 1 will represent the miter for that part shown in 
plan from 2 L to 6 L , and the cut shown from P 1 to O 1 in the pattern will 
represent the cut for that part shown in plan from 2 L to 6 J . The 
lower cut of the jack bar remains the same as that shown in the pattern. 
The half pattern for the end of the hood is shown in Fig. 179, and 
is obtained as follows: Draw any vertical line as A B, upon which 
place the stretchout of the section of the hood mn o pin Fig. 178, as 
shown by similar letters m n o p on A B in Fig. 179. At right angles 
to A B and through the small letters draw lines, making them equal in 
length, (measuring from the line A B) to points having similar letters 
in Fig. 178, also measuring from the center line A B. Connect points 
shown in Fig. 179, which is the half pattern for the end of the hood. 
For the half pattern for the end of the outside ventilator, take the 

A 



HALF PATTERN 

FOR — » 

END OF HOOD 







2* 
3" 

4-" 
H 
G 




\ 


HALF Pv 
FOR^ 
OUTSID 


\TTERN 
ID OF 
EVENT 



HALF PATTERN 

FOR END OF 

INSIDE VENT 



Fig. 179. 



Fig. 180. 



Fig. 181. 



stretchout of hi jk I'm Fig. 178 and place it on the vertical line A B in 
Fig. 180 as shown by similar letters, through which draw horizontal 
lines making them in length, measuring from A B, equal to similar 
letters in Fig. 178, also measuring from the center line A B. Connect 
the points as shown in Fig. 180 which is the desired half pattern. In 
Fig. 181 is shown the half pattern for the end of the inside ventilator, 
the stretchout of which is obtained from F 1" 2" 3" 4" H G in Fig. 178, 
the pattern being obtained as explained in connection with Figs. 179 
and 180. 

When a skylight is to be constructed on which the bars are of such 
lengths that the glass cannot be obtained in one length, and a cross bar 
or clip is required as shown by B, in Fig. 150, which miters against the 
main bar, the pattern for this intersecting cut is obtained as shown in 



152 



SHEET METAL WORK 



Fig. 182. Let A represent the section of the main bar, B the elevation 
of the cross bar, and C its section. Note how this cross bar is bent so 
that the water follows the direction of the arrow, causing no leaks be- 
cause the upper glass a is bedded in putty, while the lower light b is 
capped by the top flange of the bar C (See Fig. 150). Number all of 
the corners of the section C as shown, from 1 to 8, from which points 
draw horizontal lines cutting the main bar A at points 1 to 8 as shown. 
At right angles to the lines in B draw the vertical line D E upon wh?ch 



1 2 




14'' 



PATTERN FOR 
C&OSS BAR 



&'\ 



Fig. 182. 

place the stretchout of the cross bar C, shown by similar figures, 
through which draw horizontal lines, intersecting them with lines 
drawn parallel to D E from similar numbered intersections against the 
main bar A, thus obtaining the points of intersections 1' to 8' in the 
pattern. Trace a line through points of intersections thus obtained 
which will be the pattern for the end cut of the cross bar. 

In Fig. 183 is shown a carefully drawn working section of the 
turret sash shown in Fig. 168 at A, These sashes are operated by 



SHEET METAL WORK 



153 



means of cords, chains or gearings from the inside, the pivot on which 
they turn being~shown by R S in Fig. 183. The method of obtaining 
the patterns for these sashes will be omitted, as they are only square and 
butt miters which the student will have no trouble in developing, pro- 
viding he understands the construc- 
tion. This will be made clear by 
the following explanation: 

A B represents the upper part of 
the turret proper with a drip bent on 
same, as shown at B, against which 
the sashes close, and a double seam, 
as shown at A, which makes a tight 
joint, takes out the twist in bending, 
and avoids any soldering. This up- 
per part A B is indicated by C in 
Fig. 168, over which the gutter B is 
placed as shown by X U Y in Fig. 
183. C D represents the lower part 
of the turret proper or base, which 
fits over the wooden curb W, and is 
indicated by D in Fig. 168. E in 
Fig. 183 represents the mullion 
made from one piece of metal and 
double seamed at a. This mullion 
is joined to the top and bottom. 
The pattern for the top end of the 
mullion would simply show a square 
cut, while the pattern for the bot- 
tom would represent a butt miter 
against the slant line i j. Before forming up this mullion the holes 
should be punched in the sides to admit the pivot R S. These mullions 
are shown in position in Fig. 168 by E E, etc. 

F G in Fig. 183 represents the section of the side of the sash below 
the pivot T. Notice that this lower half of the side of the sash has a 
lock attachment which hooks into the flange of the mullion E at F. 
While the side of the sash is bent in one piece, the upper half, above the 
pivot T, has the lock omitted as shown by J K. Thus when the sash 
opens, the upper half of the sides turn toward the inside as shown by 




Fie. 183. 



154 



SHEET METAL WORK 



the arrow at the top, while the lower half swings outward as shown by 
the arrow at the bottom. When the lower half closes, it locks as shown 
at F, which makes a water-tight joint; but to obtain a water-tight joint 
for the upper half, a cap is used, partly shown by L M, into which the 
upper half of the side of the sash closes as shown at M. This cap is 
fastened to the upper part of the mullion E with a projecting hood / 
which is placed at the same angle as the sash will have when it is 
opened as shown by e e f and d d' or by the dotted lines. 

The side of the sash just explained is shown in Fig. 168 at H. 
The pattern for the side of the sash has a square cut at the top, mitering 
with H I at the bottom, in Fig. 183, the same as a square miter. H I 
represents the section of the bottom of the sash. Note where the metal 
is doubled as at b, against which the glass rests in line with the rabbet 
on the side of the sash. A beaded edge is shown at H which stiffens it. 
This lower section is shown in Fig. 168 by G and has square cuts on 
both ends. N O in Fig. 183 shows the section of the top of the sash 

The flange N in Fig. 183 is flush with the out- 
side of the glass, thereby allowing 
the glass to slide into the grooves 
in the sides of the sash. After the 
glass is in position the angle P is 
tacked at n. A leader is attached 
to the gutter Y as shown by B° in 
Fig. 168. While the method of 
construction shown in Fig. 183 is 
generally employed, each shop 
has different methods; what we 
have aimed to give is the general construction in use, after knowing 
which, the student can plan his own construction to suit the conditions 
which are apt to arise. 

In the following illustrations, Figs. 184 to 187, it will be explained 
how to obtain the true lengths of the ventilator, ridge, hip, jack, and 
common bars in a hipped skylight, no matter what size the skylight 
may be. Using this rule only one set of patterns are required, as for 
example, those developed in connection with Figs. 178, 179, 180, and 
181, which in this case has one-third pitch. If, however, a skylight 
was required whose pitch was different than one-third, a new set of 
patterns would have to be developed, to which the rule above mention- 



shown in Fig. 168 by F. 




12 11 10 



8 7 6 5 4. 

Fig. 184. 



SHEET METAL WORK 



155 



ed would also be applicable for skylights of that particular pitch. 
Using this rule it should be understood that the size of the curb, or 
frame, forms the basis for all measurements, and that one of the lines 
or bendsof the bar should meet the line of the curb as shown in Fig. 178, 
where the bottom of the bar E in the half section meets the line of the 
curb c 4' at 4', and the ridge at the top at 4'. Therefore when laying 




12 11 10 



Fig. 185. 

out the lengths of the bars, they would have to be measured on the line 
4 of the bar E from 4' to 4" on the patterns, as will be explained as we 
proceed. 

The first step is to prepare the triangles from which the lengths 
of the common and jack bars are obtained, also the lengths of the hip 
bars. After the drawings and patterns have been laid out full size 
according to the principles explained in Fig. 178, take a tracing of the 
triangle in the half section D C 4' and place it as shown by A 12 O, in 
Fig. 184. Divide O 12, which 



u 

i i 


— &'-o" *J 


\I6" 
J 

/ 


16" 

V 


16" 


16" 

c 


16" 


16"/ 
J * 


/ 






J 



16"/ T 



o 
I 



will be 12 inches in full size, into 

quarter, half-inches, and inches, 

the same as on a 2-foot rule, as 

shown by the figures O to 12. 

From these divisions erect lines 

until they intersect the pitch A O 

which completes the triangle for 

obtaining the true lengths of jack 

and common bars for any size skylight. In similar manner take 

tracing of N R 4 P in the diagonal elevation in Fig. 178 and 

place it as shown by B 12 O in Fig. 185. The length 12 O then 

becomes the base of the triangle for the hip bar in a skylight whose 

base of the triangle for the common and jack bars measures 12 inches 



Fig. 186. 



156 



SHEET METAL WORK 




as shown in Fig. 184, the heights A 12 in Fig. 184 and B 12 in Fig. 185 
being equal. Now divide 12 O in 12 equal spaces which will represent 
inches when obtaining the measurements for the hip bar. Divide 
each of the parts into quarter-inches as shown. From these devisions 
erect lines intersecting the hypothenuse or pitch line B O as shown. 
To explain how these triangles are used in practice, Figs. 186 and 
187 have been prepared, showing respectively a skylight without and 

with a ventilator whose curb 
measures 4 ft. x 8 ft. Three 
rules are used in connection 
with the triangles in Figs. 184 
and 185, the comprehension of 
which will make clear all that 
follows. 

Rule 1. To obtain the 
length of the ridge bar in a 
skylight without a ventilator, as in Fig. 186, deduct the short side 
of the frame or curb from the long side. 

Example : In Fig. 186, take 8 feet (long side of frame) — 4 feet 
(short side of frame) = 4 feet (length of ridge bar a b). 

Rule 2. To find the length of the ventilator in a skylight deduct 
the short side of the frame from the long side and add the width of the 
desired ventilator (in this case 4 inches, as shown in Fig. 187). 

Example: In Figure 187 take 8 feet (long side of frame) — 4 feet 
(short side of frame) = 4 feet. 4 feet + 4 inches (width of inside 
ventilator) = 4 feet 4 inches, (length of inside ventilator a' b'). To 
find the size of the outside ventilator h I and hood m p in Fig. 178 
simply add twice the distance a b and a c respectively to the above size, 
4 inches, and 4 feet 4 inches, which will give the widths and lengths of 
the outside vent and hood. 

Rule 3. To find the lengths of either common or hip bar (in any 
size skylight) deduct the width of the ventilator, if any, from the length 
of the shortest side of frame and divide the remainder by two. Apply 
the length thus obtained on the base line of its respective triangle for 
common or hip bars and determine the true lengths of the desired bars, 
from the hypothenuse. 

Example: As no ventilator is shown in Fig. 186, there will be 
nothing to deduct for it, and the operation is as follows : 4 feet (short- 



SHEET METAL WORK 



157 



est side of frame) -f- 2 = 2 feet. We have now the length with which 
to proceed to the triangle for common and hip bars. Thus the length 
of the common bar c d will be equal to twice the amount of A O in Fig. 
184, while the length of the hip bar b e in Fig. 186, will be equal to twice 
the amount of B O in Fig. 185. Referring to Figs. 186 and 187 the 
jack bars i j are spaced 16 inches, therefore, the length of the jack bar 
for 12 inches will equal A O in Fig. 184, and 4 inches equal to 4° O; 
both of which are added together for the full length. 

The lengths of the common and hip bars will be shorter in Fig. 
187 because a ventilator has been used, while in Fig. 186 a ridge bar 
was employed. To obtain the lengths of the common and hip bars in 
Fig. 187 use Rule 3: 48 inches (length of short side)— 4 inches (width 
of inside ventilator) = 44 inches; and 44 inches -f- 2 = 22 inches or 
1 foot 10 inches. Then the length of the common bar c' d' measured 
with a rule will be equal to A O in Fig. 184 and 10° O added together, 
and the length of the hip bar e' f in Fig. 187 will be equal to B O in Fig. 
185 and 10 x O added together. Use the same method where fraction- 
al parts of an inch occur. In laying out the patterns 
according to these measurements use the cuts shown 
in Figs. 178, 179, 180, and 181, being careful to 
measure from the arrowpoints shown on each pattern. 

It will be noticed in Fig. 178 we always meas- 
ure on line 4 in the patterns for the hip, common, 
and jack bars. This is done because the line 4 in 
the profiles E and E 4 come directly on the slant line 
of the triangles which were traced to Figs. 184 and 
185 and from which the true lengths were obtained. 
Where a curb might be used, as shown in Fig. 188, 
which would bring the bottom line of the bar H 
inches toward the inside of the frame b, all around, then instead of 
using the size of 4 x 8 feet as the basis of measurements deduct 3 
inches on each side, making the basis of measurements 3 ft. 9 inches 
x 7 ft. 9 inches, and proceed as explained above. 




158 SHEET METAL WORK 



ROOFING 



A good metal covering on a roof is as important as a good foun- 
dation. There are various materials used for this purpose such as terne 
plate or what is commonly called roofing tin. The rigid body, or the 
base of roofing tin, consists of thin sheets of steel (black plates) that 
are coated with an alloy of tin and lead. Where a first-class job is 
desired soft and cold rolled copper should be used. The soft copper 
is generally used for cap flashing and allows itself to be dressed down 
well after the base flashing is in position. The cold-rolled or hard cop- 
per is used for the roof coverings. In some cases galvanized sheet iron 
or steel is employed. No matter whether tin, galvanized iron, or 
copper is employed the method of construction is the same, and will 
be explained as we proceed. 

Another form of roofing is known as corrugated iron roofing, 
which consists of black or galvanized sheets, corrugated so as to secure 
strength and stiffness. Roofs having less than one-third pitch should 
be covered by what is known as flat-seam roofing, and should be cover- 
ed (when tin or copper is used) with sheets 10 x 14 inches in size rather 
than with sheets 14 x 20 inches, because the larger number of seams 
stiffens the surface and prevents the rattling of the tin in stormy 
weather. Steep roofs should be covered by what is known as standing- 
seam roofing made from 14" x 20" tin or from 20" x 28". Before any 
metal is placed on a roof the roofer should see that the sheathing boards 
are well seasoned, dry and free from knots and nailed close together . 
Before laying the tin plate a good building paper, free from acid, should 
be laid on the sheathing,or the tin plate should be painted on the under- 
side before laying. Corrugated iron is used for roofs and sides of 
buildings. It is usually laid directly upon the purlins in roofs, and 
held in place by means of clips of hoop iron, which encircle the purlins 
and are riveted to the corrugated iron about 12 inches apart. The 
method of constructing flat and double-seam roofing, also corrugated 
iron coverings, will be explained as we proceed. 

TABLES 

The following tables will prove useful in figuring the quantity of 
material required to cover a given number of square feet. 



SHEET METAL WORK 



159 



FLAT-SEAM ROOFING 
Table showing quantity of 14 x 20-inch tin required to cover a given 
number of square feet with flat seam tin roofing. A sheet of 14 x 20 inches with 
with J-inch edges measures, when edged or folded, 13 x 19 inches or 247 
square inches. In the following all fractional parts of a sheet are counted a 
full sheet. 





Sheets 
required 


O *i 


•a 




fi & 

Cfi $ 

u 




a> ii 
u 


100 


59 


330 


193 


560 


327 


780 


455 


110 


65 


340 


199 


570 


333 


790 


461 


120 


70 


350 


205 


580 


339 


800 


467 


130 


76 


360 


210 


590 


344 


810 


473 


140 


82 


370 


216 


600 


350 


820 


479 


150 


88 


380 


222 


610 


356 


830 


484 


160 


94 


390 


228 


620 


362 


840 


490 


170 


100 


400 


234 


630 


368 


850 


496 


180 


105 


410 


240 


640 


374 


860 


502 


190 


111 


420 


245 


650 


379 


870 


508 


200 


117 


430 


251 


660 


385 


880 


514 


210 


123 


440 


257 


670 


391 


890 


519 


220 


129 


450 


263 


680 


397 


900 


525 


230 


135 


460 


269 


690 


403 


910 


531 


240 


140 


470 


275 


700 


409 


920 


537 


250 


146 


480 


280 


710 


414 


930 


543 


260 


152 


490 


286 


720 


420 


940 


549 


270 


158 


500 


292 


730 


426 


950 


554 


280 


164 


510 


298 


740 


432 


960 


560 


290 


170 


520 


304 


750 


438 


970 


566 


300 


175 


530 


309 


760 


444 


980 


572 


310 


181 


540 


815 


770 


449 


990 


578 


320 


187 


550 


321 











1000 square feet, 583 sheets. 
A box of 112 sheets 14 x 20 inches will cover approximately 192 square feet. 

Example. How much 14 x 20 inch tin with |-inch edges is re- 
quired to cover a roof 20 feet x 84 feet? Take 20 X 84 = 1,680 
square feet. 

Referring to the table for Flat Seam Roofing, 1000 square feet require 
583 sheets and 680 square feet require 397 sheets, making a total of 
980 sheets. 

It should be understood that this amount is figured on the basis 
of 247 square inches in an edged sheet, which will be a trifle less when 
the sheets are laid on the roof. 

Example. What quantity of 20 x 28-inch tin will be required to 
lay a standing seam roof, measuring 37 feet long x 45 feet in width? 
Take 37 X 45 - 1,665 square feet, or 16 squares and 65 feet. Refer- 
ring to the table for Standing Seam Roofing, 16 squares require 4 
boxes and 48 sheets, and 65 feet require 20 sheets, making a total of 4 
boxes and 68 sheets. 



160 



SHEET METAL WORK 



STANDING-SEAM ROOFING 

Table showing the quantity of 20 X 28-inch tin in boxes, and sheets 

required to lay any given standing-seam roof. 



SQ. FEET 


SHEETS 


SQUARES 


SQ. FEET 


BOXES 


SHEETS 


SQUARES 


BOXES 


SHEETS 


1 


1 




68 




21 


35 


9 


77 


2 


1 




69 




21 


36 


9 


108 


3 


1 




70 




22 


37 


10 


27 


4 


2 




71 




22 


88 


10 


68 


5 


2 




72 




22 


30 


10 


89 


6 


2 




73 




22 


40 


11 


8 


7 


3 




74 




23 


41 


11 


39 


8 


3 




75 




23 


42 


11 


70 


9 


3 




76 




23 


43 


11 


101 


10 


4 




77 




24 


44 


12 


20 


11 


4 




78 




24 


45 


12 


51 


12 


4 




79 




84 


46 


12 


82 


13 


4 




80 




25 


47 


13 


1 


14 


5 




81 




25 


48 


13 


82 


15 


5 




82 




25 


49 


13 


63 


16 


5 




83 




25 


50 


13 


94 


17 


6 




84 




26 


51 


14 


13 


18 


6 




85 




26 


5S 


14 


44 


19 


6 




86 




26 


53 


14 


75 


20 


7 




87 




27 


54 


14 


106 


21 


7 




88 




27 


55 


15 


25 


22 


7 




89 




27 


56 


15 


56 


23 


7 




90 




28 


57 


15 


87 


24 


8 




91 




28 


58 


16 


6 


25 


8 




92 




28 


59 


16 


37 


26 


8 




93 




28 


60 


16 


68 


27 


9 




94 




29 


61 


16 


99 


28 


9 




95 




29 


62 


17 


18 


20 







96 




29 


63 


17 


49 


30 


10 




07 




30 


64 


17 


80 


31 


10 




98 




30 


65 


17 


111 


32 


10 




99 




30 


66 


18 


30 


33 


10 




100 




31 


67 


18 


61 


34 


11 


1 






31 


68 


18 


92 


35 


11 


2 






62 


69 


19 


11 


36 


11 


3 






93 


70 


19 


42 


37 


12 


4 




1 


12 


71 


19 


73 


88 


12 


5 




1 


43 


72 


19 


104 


39 


12 


6 




1 


74 


73 


20 


23 


40 


13 


7 




1 


105 


74 


20 


54 


41 


13 


8 




2 


24 


75 


20 


85 


42 


13 


9 




2 


55 


76 


21 


4 


43 


13 


10 




3 


86 


77 


21 


35 


44 


14 


11 




3 


5 


78 


21 


66 


45 


14 


12 




3 


36 


79 


21 


97 


46 


14 


13 




3 


67 


80 


22 


16 


47 


15 


14 




3 


98 


81 


22 


47 


48 


15 


15 




4 


17 


82 


2:2 


78 


49 


15 


16 




4 


48 


83 


22 


109 


50 


16 


17 




4 


79 


84 


23 


28 


51 


16 


18 




4 


110 


85 


23 


59 


52 


16 


19 




5 


29 


86 


23 


90 


53 


16 


20 




5 


60 


87 


24 


9 


54 


17 


21 




5 


91 


88 


24 


40 


55 


17 


22 




6 


10 


89 


24 


71 


56 


17 


23 




6 


41 


90 


24 


102 


57 


18 


24 




6 


72 


91 


25 


21 


58 


18 


25 




6 


103 


92 


25 


52 


59 


18 


26 




7 


22 


93 


25 


83 


60 


19 


27 




7 


58 


94 


26 


2 


61 


19 


28 




7 


84 


95 


26 


33 


62 


19 


29 




8 


8 


96 


26 


64 


63 


19 


80 




8 


84 


97 


26 


95 


64 


so 


81 




8 


65 


98 


27 


14 


65 


SO 


82 




8 


96 


99 


27 


45 


66 


SO 


83 




9 


15 


100 


87 


76 


67 


21 


34 




9 


46 









Size of sheet before working, 20 X 28 inches. 
Square inches per sheet exposed 479| inches. 



Exposed on roof 27Xl7f inches. 
Sheets per box 112. 



SHEET METAL WORK 



161 



NET WEIGHT PER BOX TIN PLATES 
Basis 14 X 20, 112 



Trade term . . . 
Weight per box, lb. 



Size of 
sheets 



x 14 
X 20 

X 28 
X 20 
X 22 



11% X 23 



X 12 
X 24 
X IS 
X 26 
X 14 
X 28 
X 15 
X 16 
X 17 
X 18 
X 19 
X 20 
X 21 
X 22 
X 23 
X 24 
X 26 
X 20 
it X 31 
11 Ji X 22% 
13^ x 1734 
13jf x 19K 
1314 x 19^ 
13^ x 19K 
14 X 18% 
14 x 19% 
14 
14 



X 21 
X 22 



it x. 22 

14 x 22% 
15^ x 23 



Sheets 
per box 



225 
112 
112 
225 
225 
325 
225 
112 
225 
112 
225 
112 
225 
225 
225 
112 
112 
112 
112 
112 
112 
112 
112 
112 
112 
112 
112 
112 
112 
112 
124 
120 
112 
112 
112 
112 



80-lb. 
80 



80 
80 
160 
114 
138 
151 
83 
82 
97 
97 
112 
112 
129 
146 
165 
93 
103 
114 
126 
138 
151 
164 
193 
91 
124 
73 
60 
73 
75 
76 
83 
83 
84 
88 
89 
102 



85-lb. 



85 

85 

170 

121 

147 

161 

87 

87 

103 

103 

119 

119 

137 

155 

175 

98 

110 

121 

134- 

147 

161 

175 

205 

97 

132 

78 

71 

77 

80 

81 



108 



90-lb. 
90 



90 

90 

180 

129 

156 

170 

93 

93 

109 

109 

126 

126 

1*5 

lo5 

186 

104 

116 

129 

142 

156 

170 

185 

217 

103 

140 

82 

76 

82 

85 

86 

93 

93 

95 

99 

100 

115 



95-lb. 
95 



95 
95 
190 
136 
164 
179 
98 
98 
115 
115 
133 
133 
153 
174 
196 
110 
122 
136 
150 
164 
179 
195 
229 
109 
147 
87 
80 
87 
89 
90 
98 
98 
100 
105 
106 
121 



100-lb. 


IC 


100 


107 


100 


107 


100 


107 


200 


214 


143 


153 


172 


184 


189 


202 


103 


110 


103 


110 


121 


129 


121 


129 


140 


150 


140 


160 


161 


172 


183 


196 


206 


221 


116 


124 


129 


138 


143 


153 


158 


169 


172 


184 


189 


202 


204 


220 


241 


258 


114 


122 


155 


166 


91 


98 


84 


90 


91 


97 


94 


100 


95 


102 


103 


110 


103 


110 


105 


112 


110 


118 


111 


119 


127 


136 



IX L 

128 



128 
128 
256 
183 
333 
243 
133 
133 
154 
154 
179 
179 
206 
234 
264 
148 
165 
183 
202 
231 
242 
263 
309 
146 
198 



IX 
135 



135 
135 
270 
193 
234 
255 
139 
139 
163 
163 
189 
189 
217 
247 
279 
158 
174 
193 
213 
234 
255 
278 
826 
154 
209 



IXX 


IXXX ] 


155 


175 


155 


175 


155 


175 


310 


350 


221 


250 


268 


302 


293 


331 


159 


180 


159 


180 


187 


211 


187 


211 


217 


245 


217 


245 


249 


281 


283 


320 


320 


361 


179 


202 


200 


326 


221 


250 


244 


276 


268 1 


302 


299 


331 


319 


860 


374 


422 


177 


200 


240 


271 



ixxxs 

195 



195 
195 
390 
279 
337 
368 
201 
201 
235 
235 
273 
273 
313 
357 
408 
236 
251 
279 
307 
337 
368 
401 
471 
223 
302 



STANDARD WEIGHTS AND GAUGES OF TIN PLATES 



Trade term 

Nearest wire gauge No. 
Weight, square foot, lb. 
Weight, box, 14 x 20, lb. 

Trade term 

Nearest wire gauge No. 
Weight, square foot, lb. 
Weight, box, 14 x 20, lb.. 



65-lb. 


70-lb. 


75-lb. 


80-lb. 


85-lb. 


90-lb. 


95-lb. 


35 


35 


34 


33 


32 


31 


31 


.298 


.322 


.345 


.367 


.390 


.413 


.436 


65 


70 


75 


80 


85 


90 


85 



100-lb. 

30 

.459 

100 



IC 


IXL 


IX 


IXX 


IXXX 


IXXXX 


30 


28 


28 


27 


26 


25 


.491 


.588 


.619 


.712 


.803 


895 


107 


128 


135 


155 


175 


195 



IXXXXX 

24 
.987 
215 





IC 14 x 20 


IC 20 x 28 


IX 14 X 20 


IX 20 X 28 


Black olates before coating . . 


lb. 
95 to 100 


lb. 

190 to 200 


lb. • 
125 to 130 


lb. 
250 to 260 


When coated the plates 


115 to 120 


230 to 240 


145 to 150 


290 to 300 







162 



SHEET METAL WORK 



OTHER FORMS OF METAL ROOFING 

There is another form of roofing known as metal slates and shin- 
gles, pressed in various geometrical designs with water-tight lock attach- 
ments so that no solder is required in 
laying the roof. Fig. 189 shows the 
general shape of these metal shingles 
which are made from tin, galvanized 
iron, and copper, the dots a a a a 
representing the holes for nailing to 
the wood sheathing. In Fig. 190, A 
represents the side lock, showing the 
first operation in laying the metal slate 
or shingle on a roof, a representing the 
nail. B, in the same figure, shows the 
metal slate or shingle in position cover- 
ing the nail b, the valley c of the bottom 
slate allowing the water, if any, to 
flow over the next lower slate as in A in Fig. 189. 

In Fig. 191 is shown the bottom slate A covered by the top slate B, 
the ridges a a a keeping the water from 
backing up. Fig. 192 shows the style of 
roof on which these shingles are employed, 
that is, on steep roofs. Note the con- 
struction of the ridge roll, A and B in 
Fig. 192, which is first nailed in position 
at a a etc., after which the shingles B are 
slipped under the lock c. Fig. 193 shows 
a roll hip covering which is laid from the 
top downward, the lower end of the hip having a projection piece for 
nailing at a, over which the top end of the next piece is inserted, thus 




Fig. 189. 




Sheathing board 




SHEATHING BOARD 

Fig. 190. 




Fig. 191. 

covering and concealing the nails. Fig. 194 represents a perspective 
view of a valley with metal slates, showing how the slates A are 
locked to the fold in the valley B. There are many other forms of 



SHEET METAL WORK 



163 



metal shingles, but the shapes shown herewith are known as the 
Cortright patents. 

TOOLS REQUIRED 

Fig. 195 shows the various hand tools required by the metal roof- 
er; starting at the left we have the soldering copper, mallet, scraper, 




Fig. 192. 



stretch-awl, shears, hammer, and dividers. In addition to these hand 
tools a notching machine is required for cutting off the corners of the 





Fig. 193. 

sheets, and roofing folders are re- 
quired for edging the sheets in flat- 
seam roofing, and hand double seamer 
and roofing tongs for standing-seam 
roofing. The roofing double seamer 
and squeezing tongs can be used for 
standing-seam roofing (in place of the 
hand double seamer), which allow the 
operator to stand in an upright position if the roof is not too steep. 

ROOF MENSURATION 
While some mechanics understand thoroughly the methods of 



164 



SHEET METAL WORK 



laying the various kinds of roofing, there are some, however, who do 
not understand how to figure from architects' or scale drawings the 
amount of material required to cover a given surface in a flat, irregular 
shaped, or hipped roof. The modern house with its gables and va- 




Fig. 195. 
rious intersecting roofs, forming hips and valleys, render it necessary to 
give a short chapter on roof measurement. In Figs. 196 to 198 in- 
clusive are shown respectively the plans with full size measurements 
for a flat, irregular,and intersected hipped roof, showing how the length 
of the hips and valleys are obtained direct from 
the architects' scale drawings. 

The illustrations shown herewith are not 
drawn to a scale as architects' drawings will be, 
but the measurements on the diagrams are as- 
sumed, which will clearly show the principles 
which must be applied when figuring from scale 
drawings. Assuming that the plans from which 
we are figuring are drawn to a quarter-inch scale, 
then when measurements are taken, every quarter 
inch represents one foot. £ inch = 6 inches, ^ 
inch = 3 inches, etc. If the drawings were drawn to a half-inch 
scale, then \ inch =12 inches, \ inch = 6 inches, \ inch - 3 inches, 
y 1 ^ inch = \\ inches, etc. 

A B C D in Fig. 196 represents a flat roof with a shaft at one side 
as shown by a b c d. In a roof of this kind we will figure it as if there 
was no air shaft at all. Thus 64 feet X 42 feet = 2,688 square feet. 
The shaft is 12.5 X 6 feet - 75 square feet; then 2,688 feet - 75 feet - 




SHEET METAL WORK 



165 



XT 

u 

o 

JA 



2,613 square feet of roofing, to which must be added an allowance for 
the flashing turning up against and into the walls at the sides. 

In Fig. 197 is shown a flat roof with a shaft at each side, one shaft 
being irregular, forming an irregular shaped A B 

roof. The rule for obtaining the area is sim- 
ilar to that used for Fig. 196 with the exception 
that the area of the irregular shaft x x x x in 
Fig. 197 is determined differently to that of the 
shaft bcde: Thus A B C D = 108 feet X 45 
feet = 4,860 square feet. Find the area of b c 
d e which is 9.25 X 39.5 - 365.375 or 365f 
square feet. To find the area of the irregular 
shaft, bisect xx and xx and obtain a a, 
measure the length of a a which is 48 feet, and 
multiply by 9. Thus 48 X 9 = 412, and 412 
+ 365.375 — 777.375. The entire roof minus 
the shafts = 4,860 square feet - 777.375 - 
4,082.625 square feet of surface in Fig. 197. 

In Fig. 198 is shown the plan, front, and side elevations of an in- 
tersected hipped roof. A B C D represents the plan of the main build- 



.1 



o 

b J 

CO 

o 



a e 



tJu 



9'-3 



- AS'-O"- 
Fig. 197. 




SIDE 
^XEUEVATION 



Fig. 198. 

ing intersected by the wing E F G H. We will first figure the main 
roof as if there were no wing attached and then deduct the space taken 



lt>6 SHEET METAL WORK 

up by the intersection of the wing. While it may appear difficult to 
some to figure the quantities in a hipped roof, it is very simple, if the 
rule is understood. As the pitch of the roof is equal on four sides the 
length of the rafter shown from O to N in front elevation represents 
the true length of the pitch on each side. The length of the building 
at the eave is 90 feet and the length of the ridge 48 feet. Take 
90 - 48 = 42, and 42 ■*- 2 = 21. Now either add 21 to the length of the 
edge or deduct 21 from the length of the eave, which gives 69 feet as 
shown from S to T. The length of the eave at the end is 42 feet and 
it runs to an apex at J. Then take 42 feet -r- 2 = 21, as shown from T 
to U. If desired the hip lines A I, J B and J C can be bisected, obtain- 
ing respectively the points S, T, and U, which when measured will be 
of similar sizes; 69 feet and 21 feet. As the length of the rafter O N 
is 30 feet, then multiply as follows: 69 X 30 - 2070. 21 X 30 - 630. 
Then 630 + 2,070 - 2,700, and multiplying by 2 (for opposite sides) 
gives 5,400 square feet or 54 squares of roofing for the main building. 
From this amount deduct the intersection E L F in the plan as follows : 

The width of the wing is 24 feet 6 inches and it intersects the main 
roof as shown at E L F. Bisect E L and L F and obtain points W and 
V, which when measured will be 12 feet 3 inches or one half of HG, 
24 feet 6 inches. The wing intersects the main roof from Y to F 1 in the 
side elevation, a distance of 18 feet. Then take 18 X 12.25 - 220.5. 
Deduct 220.5 from 5400 - 5,179.5. The wing measures 33 feet 6 
inches at the ridge L M, and 21 feet 6 inches at the eave F G, thus 
making the distance from V to X =27 feet 6 inches. The length of 
the rafter of the wing is shown in front elevation by P R, and is 18 feet. 
Then 18 X 27.5 = 495, and multiplying by 2 (for opposite side), gives 
995 sq. ft. in the wing. We then have a roofing area of 5,179.5 square 
feet in the main roof and 995 square feet in the wing, making a total of 
6,174.5 square feet in the plan shown in Fig. 198. 

If it is desired to know the quantity of ridge, hips, and valleys in 
the roof, the following method is used. The ridge can be taken from 
the plans by adding 48' + 33'6" - 81' - 6". For the true length of 
the hip I D in the plan, drop a vertical line from I 1 in the front elevation 
until it intersects the eave line 1°. On the eave line extended, place the 
distance I D in the plan as shown from 1° to D° and draw a line from 
D° to I 1 which will be the true length of the hip I D in the plan. Multi- 
ply this length by 4, which will give the amount of ridge capping re- 



SHEET METAL WORK 



167 



quired. This length of hip can also be obtained from the plan by tak- 
ing the vertical height of the roof 1° I' in the elevation and placing it at 
right angles to I D in the plan, as shown, from I to I 2 , and draw a line 
from I 2 to D which is the desired length. 

For the length of the valley L F in the plan, drop a vertical line 
from F 1 in the side elevation until it intersects the eave line at F°. 
Take the distance F L in the plan and place it as shown from F° to L°, 
and draw a line from L° to F 1 , which is the true length of the valley 
shown by L F in the plan. Multiply this length by 2, which will give 
the required number of feet of valley required. This length of valley 
can also be obtained from the plan by taking the vertical height of the 
roof of the wing, shown by F° F 1 in the side elevation, and placing it at 
right angles to F L in the plan, from L to P, and draw a line from P 
to F which is the desired length similar to F 1 L° in the side elevation. 

FLAT-SEAM ROOFING 

The first step necessary in preparing the plates for flat seam 
roofing is to notch or cut off the four corners of the plate as shown in 
Fig. 199 which shows the plate as it is taken from the box, the shaded 
corners a a a a representing the corners which are 
notched on the notching machine or with the shears. 
Care must be taken when cutting off these corners not 
to cut off too little otherwise the sheets will not edge 
well, and not to cut off too much, otherwise a hole will 
show at the corners when the sheets are laid. To find 
the correct amount to be cut off proceed as follows: 

Assuming that a £-inch edge is desired, set the dividers at £ inch 
and scribe the lines b a and a c on the sheet shown in Fig. 199, and, 
where the lines intersect at a, draw the line d e at an angle of 45 degrees, 
which represents the true amount and true angle to be 
cut off on each corner. After all the sheets have been 
notched, they are edged as shown in Fig. 200, the long 
sides of the sheet being bent right and left, as shown at 
a, while the short side is bent as shown at 6, making 
the notched corner appear as at e. In some cases 
after the sheets are edged the contract requires that the 
sheets be painted on the underside before laying. This is usually 
done with a small brush, being careful that the edges of the sheets 




Fig. 199. 



Fig. 200. 



168 



SHEET METAL WORK 



are not soiled with paint, which would interfere with soldering. Be- 
fore laying the sheets the roof boards are sometimes covered with an 
oil or rosin-sized paper to prevent the moisture or fumes from below 
from rusting the tin on the underside. As before mentioned, the same 
method used for laying tin roofing would be applicable for laying 
copper roofing, with the exception that the copper sheets would 
have to be tinned about 1| inches around the edges of the sheets 
after they are notched, and before they are edged. 

In Fig. 201 is shown how a tin roof is started and the sheets laid 
when a gutter is used at the eaves with a fire wall at the side. A repre- 




Fig. 201. 

sents a galvanized iron gutter with a portion of it lapping on the roof, 
with a lock at C. In hanging the gutter it is flashed against the fire 
wall at J; after which the base flashing D D is put in position, flashing 
out on the roof at E, with a lock at F. Where the base flashing E 
miters with the flange of the gutter B it is joined as shown at b, allowing 
the flange E of the base flashing as shown by the dotted line a. As the 
water discharges at G, the sheets are laid in the direction of the arrow 
H, placing the nails at least 6 inches apart, always starting to nail at 
the butt e e, etc. Care should be taken when nailing that the nail heads 
are well covered by the edges, as shown in W, by a. Over the base 
flashing D D J the cap flashing L is placed, allowing it to go into the 
wall as at O. 



SHEET METAL WORK 



169 



When putting in base flashings there are two methods employed. 
In Fig. 202 is shown a side flashing between the roof and parapet wall. 
A shows the flashing turning out on the roof at B, with a lock C, attach- 
ed and flashed into the wall four courses of brick above the roof line, 
as shown at D, where wall hooks and 
paintskins or roofer's cement are used to 
make a tight joint. Flashings of this 
kind should always be painted on the 
underside, and paper should be placed 
between the brick work and metal, be- 
cause the moisture in the wall is apt to 
rust the tin. This method of putting in 
flashing is not advisable in new work, 
because when the building is new, the walls and beams are liable 
to settle and when this occurs the flange D tears out of the wall, and the 
result is disagreeable leaks that stain the walls. When a new roof is 
to be placed on an old building where the walls and copings are in 
place and the brick work and beams have settled, there is not so much 
danger of leakage. 

The proper method of putting in flashings and one which allows 
for the expansion and contraction of the metal and the settlement of the 
building is shown in Fig. 203, in which A shows the cap flashings, 




Fig. 202. 





Fig. 203. Fig. 204. 

painted with two coats of paint before using. When the mason has 
built his wall up to four courses of brick above the roof line the cap 
flashing A is placed in position and the wall and coping finished; the 
base flashing B is then slipped under the cap A. In practice the cap 
flashing is cut 7 inches, then bent at right angles through the center, 
making each side a and h 3| inches. The base flashing B is then 
slipped under the cap flashing A as shown at C. 



170 



SHEET METAL WORK 



CL 


CL 




VALLEY 

L 


SHEET 



m 



Where the cost is not considered and a good job is desired, it is 
better to use sheet lead cap flashings in place of tin. They last longer, 
do not rust, and can be dressed down well to lay tight onto the base 
flashings. Into the lock C the sheets are attached. After the sheets 
are laid the seams are flattened down well by means of a heavy mallet, 
with slightly convex faces, after which the roof 
is ready for soldering,, When a base flashing 
is required on a roof which abuts against a wall 
composed of clap boards or shingles as shown 
in Fig. 204, then, after the last course of tin A 
Fig. 205. nas b een jaj^ tj le flashing g Tvith the lock a is 

locked into the course A and extends the required distance under the 

boards D. The flashing should always be painted and allowed to dry 

before it is placed in position. In the previous figures it was shown 

how the sheets are edged, both sides being edged right and left. In 

Fig. 205 is shown what is known 

as a valley sheet, where the short 

sides are edged both one way, as 

shown at a a, and the long sides 

right and left as shown at bb. 

Sheets of this kind are used when 

the water runs together from two 

directions as shown by A in Fig. 

206. By having the locks a and a turned one way the roof is laid in 

both directions. 

Fig. 207 shows a part plan of a roof and chimney A, around which 

the flashing B C D E is to be placed, and explains how the corners C 

and D are double seamed, 
whether on a chimney, 
bulkhead, or any other ob- 
ject on a roof when the 
water flows in the direction 
of the arrow F. The first 
operation is shown at a and 
the final operation at 6. 




Fig. 206. 




Fig. 207. 



Thus it will be seen that the water flows past the seam and not against 
it. In laying flat seam roofing especially when copper is used, allow- 
ance must be made for the expansion and contraction of the sheets. 



SHEET METAL WORK 



171 



Care should be taken not to nail directly through the sheet as is shown 
in W, Fig. 201. While this method is generally employed in tin 
roofing, on a good job, as well as on copper roofing, cleats as shown at 
D in Fig. 208 should be used. 

To show how they are used, A and B represent two locked-edged 
sheets. The lock on the cleat D is locked into the edge of the sheets 
and nailed into the roof boards at a b c and d, ar as often as required. 



=fe£ 



d 

./2_ 



^ 



o 



Fig. 208. 

In this manner the entire roof can be fastened with cleats without 
having a nail driven into the sheets, thereby allowing for expansion 
and contraction of the metal. The closer these cleats are placed, the 
firmer the roof will be and the better the seams will hold. By using 
fewer cleats, time may be saved in laying the roof, but double this time 
is lost when soldering the seams, for the heat of the soldering copper 




Fig. 209. 

will raise the seams, causing a succession of buckles, which retard 
soldering and require 10 per cent more solder. When the seams are 
nailed or cleated close it lays flat and smooth and the soldering is done 
with ease and less solder. 

When a connection is to be made between metal and stone or 
terra cotta, the method shown in Fig. 209 is employed. This illus- 
tration shows a stone or terra-cotta cornice A. The heavy line abed 



172 SHEET METAL WORK 

represents the gutter lining, which is usually made from 20-oz. cold- 
rolled copper. If the cornice A is of stone, the stone cutter cuts a 
raggle into the top of the cornice A as at B, dove-tail in shape, after 
which the lining a b c d is put in position as shown. Then, being care- 
ful that there is no water or moisture in the raggle B, molten lead is 
poured into the raggle and after it is cooled it is dressed down well with 
the caulking chisel and hammer. 

By having the dove-tail cut, the lead is secured firmly in position, 
holding down the edge of the lining and making a tight joint. Should 
the cornice be of terra cotta this raggle is cut into the clay before it is 
baked in the ovens. This method of making connection between 




Fig. 210. 

metal and stone is the same no matter whether a gutter or upright wall 
is to be flashed. When a flashing between a stone wall and roof is to 
be made tight, then instead of using molten lead, cakes of lead are cast 
in molds made for this purpose, about 12 inches long, and these are 
driven into the raggle B as shown in Fig. 209 at X. 

The most important step in roofing is the soldering. The style of 
soldering copper employed is shown in Fig. 210 and weighs at least 8 
pounds to the pair. When rosin is used as a flux, it is also employed 
in tinning the coppers, but when acid is used as a flux for soldering zinc 
or galvanized iron, salammoniac is used for tinning the coppers. It 
will be noticed that the soldering coppers are forged square at the ends, 
and have a groove filed in one side as shown at A. When the copper 
is turned upward the groove should be filed 
toward the lower side within J inch from 
the corner, so that when the groove is placed 
upon the seam, as shown in Fig. 211, it acts 
Fig- 2n - as a guide to the copper as the latter is 

drawn along the seam. The groove a being in the position shown, 
the largest heated surface b rests directly on the seam, "soaking" 
it thoroughly with solder. As the heat draws the solder between 
the locks, about 6 pounds of £ and f solder are required for 100 square 
feet of surface using 14 x 20-inch (in. The use of acid in soldering 
seams in a tin roof is to be avoided as acid coming in contact with the 




SHEET METAL WORK 



173 



bare edges and corners, where the sheets are folded and seamed to- 
gether, will cause rusting. No other soldering flux but good clean 
rosin should be employed. The same flux (rosin) should be used 
when soldering copper roofing whose edges have previously been 
tinned with rosin. 

We will now consider the soldering of upright seams. The solder- 
ing copper to be employed for this purpose is shaped as shown in Fig. 
212. It is forged to a wedge shape, about 1 inch wide and £ inch 

^ 




♦ Fig. 212. 

thick at the end, and is tinned on one side and the end only; if tinned 
otherwise, the solder, instead of remaining on the tinned side when 
soldering, would flow downward; by having the soldering copper tin- 
ned on one side only, the remaining sides are black and do not tend 
to draw the solder downward. The soldering copper being thus pre- 
pared, the upright seam, shown in Fig. 213, where the sheet B overlaps 
the sheet A 1", is soldered by first tacking the seam to make it lay close, 
then thoroughly soaking the seam, 
and then placing ridges of solder 
across it to strengthen the same. 
In using the soldering copper it 
should be held in the position 
shown by C, which allows the sol- 
der to flow forward and into the 
seam, while if the copper were held 
as shown by D, the solder would 
flow backward and away from the 
seam. In "soaking" the seam with 
solder the copper should be placed g ' 

directly over the lapped part, so that the metal gets thoroughly 
heated and draws the solder between the joint. It makes no differ- 
ence where this cross joint occurs; the same methods are used. 

The roof being completed, the rosin is scraped off the seams and 
the roof cleaned and painted with good iron oxide and linseed oil paint. 
Some roofers omit the scraping of rosin and paint directly over it. 
This is the cause of rusting of seams which sometimes occurs. If the 




174 



SHEET METAL WORK 



paint is applied to the rosin, the latter, with time, will crack, and the 
rain will soak under the cracked rosin to the tinsurface. Even when 
the surface of the roof is dry, by raising the cracked rosin, moisture 
will often be found underneath, which naturally tends to rust the plate 
more and more with each storm. If the rosin is removed, the entire 
tin surface is protected by paint. 

One of the most difficult jobs in flat-seams roofing is that of cover- 
ing a conical tower. As the roof in question is round in plan and taper- 
ing in elevation, it is necessary to know the 
method of cutting the various patterns for the 
sheets. In Fig. 214 ABC shows the eleva- 
tion of a tower to be covered with flat seam 
roofing, using 10 X 14-inch tin at the base. As- 
suming that the tower through B C is 10 feet 6 
inches, or 128 inches, in diameter, the circum- 
ference is obtained by multiplying 126 by 
3.1416 -which equals 395.8416, or say 396 
inches. As 10 x 14-inch plate is to be used at 
the base of the tower the nearest width which 
can be employed, and which will divide the 
space into equal spaces, is 13£ inches without 
edges, thus dividing the circumference in 30 
equal spaces. This width of 13^ inches to- 
gether with the length of the rafter A B or B C 
in elevation, will be the basis from which all the 
patterns for the various courses will be laid off. 
At any convenient place in the shop or at 
the building, stretch a piece of tar felting of 
the required length, tacking it at the four corners with nails to 
keep the paper from moving. Upon the center of the felting strike 
a chalk line as A B in Fig. 215, making it equal to the length 
of the rafter A B or A C in Fig. 214. At right angles to A B in 
Fig. 215 at either side, draw the lines B D and B C each equal to 6f 
inches, being one half of the 13| above referred to. From the points 
C and D draw lines to the apex A (shown broken). As the width of 
the sheet used is 10 inches and as we assume an edge of f inch for 
each side, thus leaving 9f inches, measure on the vertical line A B 
lengths of 9£ inches in succession, until the apex A is reached, leaving 




Fig. 214. 



SHEET METAL WORK 



175 



the last sheet at the top to come as it may. Through the points thus 

obtained on A B draw lines parallel to C D intersecting the lines A C 

and A D as shown. Then the various shapes marked 12 3 etc. will 

be the net patterns for similarly numbered 

courses. Take the shears and cut out the 

patterns on the felting and number them as 

required. 

For example, take the paper pattern 

No. 1, place it on a sheet of tin as shown in 

Fig. 216, and allow f-inch edges all around, 

and notch the corners ABC and D. Mark 

on the tin pattern "No. 1, 29 more", as 30 

sheets are required to go around the tower, 

and cut 29 more for course No. 1. Treat 

all of the paper patterns from No. 1 to the 

apex in similar manner. Of course where 

the patterns become smaller in size at the 

top, the waste from other patterns can be 

used. 

In Fig. 217 is shown how the sheets 

should be edged, always being careful to 

have the narrow side towards the top with 

the edge toward the outside, the same as in 

flat seam roofing. Lay the sheets in the 

usual manner, breaking joints as in general 

practice. As the seams are not soldered 

care must be taken to lock the edges well. 

After the entire roof is laid and before closing the seams with the mallet. 

take a small brush and 
paint the locks with thick 
white lead, then close 
with the mallet. This 
will make a water-tight 
job. After the roof is 




Fig. 215. 



PATTERN FOR 
NO.l 



29 MORE 



Fig. 216. 



| EDGED SHEET', 

FOR COURSE. 

NO.l 



Fig. 217. 

completed the finial D in Fig. 214 is put in position. 

As the method used for obtaining the patterns for the various 
sheets in Fig. 215 is based upon the principle used in obtaining the 
envelope of a right cone, some student may say that in accurate pat- 



176 



SHEET METAL WORK 



terns the line from C to D and all following lines should be curved, 
as if struck with a radius from the center A, and not straight as shown. 
To those the writer would say that the curve would be so little on a 
small pattern, where the radius is so long, that a straight line answers 
the purpose just as well in all practical work; for it would amount to 
considerable labor to turn edges on the curved cut of the sheet, and 
there is certainly no necessity for it. 

When different metals are to be connected together, as for instance 
tin roofing to copper flashing, or copper tubes to galvanized iron gut- 
ters, or zinc flashings in connection with copper linings, care must be 
taken to have the copper sheets thoroughly tinned on both sides where it 
joins to the galvanized iron, zinc, or other metal, to avoid any electroly- 
sis between the two metals. It is a fact not well known to roofers 
that if we take a glass jar and fill it with water and place it in separate- 
ly, two clean strips, one of zinc and the other of copper, and connect the 
two with a thin copper wire, an electrical action is the result, and if the 

connection remains for a long time 
(as the action is very faint) the zinc 
would be destroyed, because, it may 
be said, the zinc furnishes the fuel 
for the electrical action, the same 
as wood furnishes the fuel for the 
fire. Therefore, if the copper was 
not tinned, before locking into the 
other metal, and the joint became 
wet with rain, the coating of the 
metal would be destroyed by the 
electrical action between the two metals, and the iron would rust 
through. 

While the roofer is seldom called upon to lay out patterns for any 
roofing work occasion may arise that a roof flashing is required around 
a pipe passing through a roof of any pitch, as shown in Fig. 218, in 
which A represents a smoke or vent pipe passing through the roof B B, 
the metal roof flashing being indicated by C C. If the roof B B were 
level the opening to be cut into the flashing C C would simply be a 
true circle the same diameter as the pipe A. But where the roof 
pitches the opening in the flashing becomes an ellipse, whose minor 
axis is the same as the diameter of the pipe, and whose major axis is 




Fig. 218. 



SHEET METAL WORK 



177 



equal to the pitch a b. In Fig. 219 is shown how this opening is ob- 
tained by the use of a few nails, a string, and a pencil, which the roofer 
will always have handy. 

First draw the line A B representing the slant of the roof, and 
then make the pipe of the desired size passing through this line at its 
proper angle to the roof 
line. Next draw the center 
line R S of the pipe, as 
shown. Call the point 
where this line intersects 
the roof line, I, and the 
points where D E and C F 
intersect A B, G and H re- 
spectively. Through I draw 
K L at right angles to A B, 
making K I and I L each 
equal to the half diameter 
of the pipe. Having estab- 
lished the minor axis K L 
and the major axis G H, 
the ellipse is made by tak- 
ing I H, or half the major 
axis, as a radius, and with 
L as a center strike arcs in- Fi &- 21 9- 

tersecting the major axis, at points M and N. Drive a small nail in 
each of these two points and attach a string to the nails as shown by 
the dotted lines K M N, in such a way that when a pencil point is 
placed in the string it will reach K. Move the pencil along the 
string, keeping it taut all the time until the ellipse K H L G is ob- 
tained. Note how the position of the string changes when it reaches 
a, then b, etc. 

STANDING-SEAM ROOFING 

Another form of metal roofing is that known as standing seam, 
which is used on steep roofs not less than £ pitch, or £ the width 
of the building. It consists of metal sheets whose cross or horizontal 
seams are locked as in flat seam roofing, and whose vertical seams are 
standing locked seams, as will be described in connection with Figs. 




178 



SHEET METAL WORK 



co 




Fig. 220. 



220 to 229 inclusive. Assume that 14 x 20-inch sheets are used and 
the sheets are edged on the 20-inch sides only, as shown by A in Fig. 
220, making the sheet 13 x 20 inches. After the required number of 
sheets have been edged, and assuming that the length of the pitched 

roof is 30 feet, then as many sheets are 

Ii locked together as will be required, and 
the seams are closed with the mallet 
and soldered. In practice these strips 
are prepared of the required length in the 
shop, painted on the underside, and when 
dry are rolled up and sent to the building. 
If desired they can be laid out at the build- 
ing, which avoids the buckling caused by rolling and transportation 
from the shop to the job. 

After the necessary strips have been prepared they are bent up 
with the roofing tongs, or, what is better and quicker, the roofing edger 
for standing-seam roofing. This is a machine into which the strips of 
tin are fed, being dis- 
charged in the required 
bent form shown at A or 
B in Fig. 221, bent up 1 
inch on one side and 1| 
inches on the other side. 
Or the machine will, if lg ' 

desired, bend up If inches and lj inches, giving a f-inch finished 
doubled seam in the first case and a 1-inch seam in the second. 
When laying standing-seam roofing, in no case should any nails 
be driven into the sheets. This applies to tin, copper or galva- 
nized iron sheets. A cleat should be used, as shown 
in Fig. 222, which also shows the full size for laying 
the sheets given in Fig. 221. Thus it will be seen in 
Fig. 222 that \ inch has been added over the measure- 
ments in Fig. 221, thus allowing edges. 

These cleats shown in Fig. 222 are made from 
scrap metal; they allow for the expansion and con- 
traction of the roofing and are used in practice as shown in Fig. 223, 
which represents the first operation in laying a standing-seam roof, 
and in which A represents the gutter with a lock attached at B. The 





SHEET METAL WORK 



179 



gutter being fastened in position by means of cleats under the 
lock B — the same as in flat seam roofing — the standing seam strips 
are laid as follows: Take the strip C and lock it well into the 
lock B of the gutter A as shown, and place the cleat shown in Fig. 
222 tightly against the upright bend of the strip C in Fig. 223 as shown 
at D, and fasten it to the roof by means of a 1-inch roofing nail a. 




Fig. 223. 

Press the strip C firmly onto the roof and turn over edge b of the cleat 
D. This holds the sheet C in position. Now take the next sheet E, 
press it down and against the cleat D and turn over the edge d, which 
holds E in position. These cleats should be placed about 18 inches 




Fig. 224. Fig. 225. 

apart and by using them it will be seen that no nails have been driven 
through the sheets, the entire roof being held in position by means of 
the cleats only. 

The second operation is shown in Fig. 224. By means of the 
hand double seamer and mallet or with the roofing double seamers and 
squeezing tongs, the single seam is made as shown at a. The third 
and last operation is shown in Fig. 225 where by the use of the same 
tools the doubled seam a is obtained. In Fig. 226 is shown how the 
finish is made with a comb ridge at the top. The sheets AAA have 



SHEET METAL WORK 



on the one side the single edge as shown, while the opposite side B has 
a double edge turned over as shown at a. Then, standing seams bbb 
are soldered down to e. 

In Fig. 227 is shown how the side of a wall is flashed and counter 




Fig. 226. 

flashed. A shows the gutter, B the leader or rain water conductor, 
and C the lock on the gutter A, fastened to the roof boards by cleats 




Fig. 227. 

tjfl shown at D. The back of the gutter is flashed up against the waft 
as high as shown by the dotted line E. F represents a standing-seam 
strip locked into the gutter at H and flashed up against the wall as higl* 



SHEET METAL WORK 



181 



as shown by the dotted line J J. As the flashing J J E is not fastened 
at any part to the wall the beams or wall can settle without disturbing 
the flashing. The counter or cap flashing K K K is now stepped as 
shown by the heavy lines, the joints of the brick work being cut out to 
allow a one-inch flange ddd etc. to enter. This is well fastened with 
flashing hooks, as indicated by the small dots, and then made water- 
tight with roofer's cement. As will be seen the cap flashing overlaps the 
base flashing a distance indicated by J J and 
covers to L L; the corner is double seamed at 
ab. M shows a sectional view through the 
gutter showing how the tubes and leaders are 
joined. The tube N is flanged out as shown 
at i i, and soldered to the gutter; the leader 
O is then slipped over the tube N as shown, 
and fastened. 

In the section on Flat-Seam Roofing it 
was explained how a conical tower, Fig. 214, 
would be covered. It will be shown now 
how this tower would be covered with stand- 
ing-seam roofing. As the circumference of 
the tower at the base is 396 inches, and 
assuming that 14 x 20-inch tin plate is to 
be used at the base of the tower, the nearest 
width which can be employed and which 
will divide the base into equal spaces is 17 -^ 
inches, without edges, thus dividing the cir- 
cumference into 23 equal parts. Then the 
width of 17^ inches and the length of the 
rafter A B or AC in elevation will be the 
basis from which to construct the pattern 
for the standing seam strip, for which pro- 
ceed as follows: 

Let A B C D in Fig. 228 represent a 20-inch wide strip locked and 
soldered to the required length. Through the center of the strip draw 
the line E F. Now measure the length of the rafter A B or A C in Fig. 
214 and place it on the line E F in Fig. 228 as shown from H to F. At 
right angles to H F on either side draw F O and F L making each 
equal to S^-f inches, being one half of the 17^- above referred to. 




Fig. 228. 



182 



SHEET METAL WORK 



From points L and O draw lines to the apex H (shown broken). At 
right angles to H L and H O draw lines H P equal to 1{ inches and 
H S equal to 1| inches respectively. In similar manner draw L D and 
O C and connect by lines the points P D and S C. Then will P S C D 
be the pattern for the standing seam strip, of which 22 more will be 
required. When the strips are all cut out, use the roofing tongs and 
bend up the sides, after which they are laid on 
the tower, fastened with cleats, and double 
seamed with the hand seamer and mallet in 
the usual manner. 

If the tower was done m copper or galva- 
nized sheet iron or steel, where 8-foot sheets 
could be used, as many sheets would be cross- 
locked together as required; then metal could 
be saved, and waste avoided, by cutting the 
sheets as shown in Fig. 229 in which A B C D 
shows the sheets of metal locked together, and 
E and F the pattern sheets, the only waste be- 
ing that shown by the shaded portion. Where 
the finial D in Fig. 214 sets over the tower, the 
standing seams are turned over flat as much 
g ' as is required to receive the finial, or small 

notches would be cut into the base of the finial, to allow it to slip over 
the standing seams. Before closing the seams, they are painted with 
white lead with a tool brush, then closed up tight, which makes a good 
tight job. 

CORRUGATED IRON ROOFING AND SIDING 
Corrugated iron is used for roofs and sides of buildings. It is 
usually laid directly upon the purlins in roofs constructed as shown in 
Figs. 230 and 231, the former being constructed to receive sidings of 
corrugated iron, while in the latter figure the side walls of the building 
are brick. Special care must be taken that the projecting edges of the 
corrugated iron at the eaves and gable ends of the roof are well secured, 
otherwise the wind will loosen the sheets and fold them up. The cor- 
rugations are made of various sizes such as 5-inch, 2^-inch, l|-inch 
and f-inch, the measurements always being from A to B in Fig. 232, 
and the depth being shown by C. The smaller corrugations give a 




SHEET METAL WORK 



183 



more pleasing appearance, but the larger corrugations are stiffer and 
will span a greacer distance,thereby permitting the purlins to be further 
apart. 




Fig. 230. 

The thickness of the metal generally used for roofing and siding 
varies from No. 24 to No. 16 gauge. By actual trial made by The 




Fig. 231. 

Keystone Bridge Company it was found that corrugated iron No. 20, 

spanning 6 feet, began to give 

permanent deflection at a load of 

30 lb. per square foot, and that . 

it collapsed with a load of 60 lb. 

per square foot. The distance 

between centers of purlins should, therefore, not exceed 6 feet, and 

preferably be less than this. 




184 



SHEET METAL WORK 



TABLES 

The following tables will prove of value when desiring any infor- 
mation to which they appertain. 

MEASUREMENTS OF CORRUGATED SHEETS 
Dimensions of Sheets and Corrugations. 



a 
^ o 

St 
o 
u 


a 
OS 

& 8. 

•a 3 


.a S? 

OS 


o 

V 
CD 

n * <° 


o 


3§ fl 

£ a- 
a as 

t* ^ 9, 
o » ° 

e8 


as «a 

o 


S> 01 

i-5 o' 


5 inch. 


5 inch. 


1 inch. 


6 


34 inch. 


27 inch. 


10 feet. 


VA inch. 


2% inch. 


Vt^oYi inch. 


10 


24 inch. 


28 inch. 


10 feet. 


l^lnch. 


IK inch. 


Jb to Vi inch. 


19H 


24 inch. 


26 inch. 


10 feet. 


Ji inch. 


Ji inch. 


K inch. 


34^ 


25 inch. 


26 inch. 


8 feet. 



RESULTS OF TEST 

of a corrugated sheet No. 20, 2 feet wide, 6 feet long between supports, loaded 
uniformly with fire clay. 



Load 


Deflection 


per square foot. 


at center under load. 


lb. 


Inches. 


5 


i 


10 


1 


15 


1 


20 


1| 


25 


ll 


30 


11 


35 


24 


40 


2f 


45 


3| 


50 


4 


55 


6£ 


60 


Broke down. 



Permanent Deflection, 
load removed. 



Not noted. 



The following table shows the distance apart the supports should 
be for different gauges of corrugated sheets: 

Nos. 16 and IS „ 6 to 7 feet apart. 

Nos. 20 and 22 4 to 5 feet apart. 

No. 24 2 to 4 feet apart. 

No. 28 2 feet apart. 



SHEET METAL WORK 



185 



The following table is calculated for sheets 30^ inches wide before 
corrugating. 



a 
3 


01 

to 


43 

P. 
Lb. 


6*3 

beg M 

^ Vi o 
P. 

Lb. 


Weight per square of 100 square feet, when 
laid, allowing 6 inches lap in length and 
2^ inches or one corrugation in width of 
sheet, for sheet lengths of: 


Weight 
square ft., 
, galva- 
nized 


5 feet 


6 feet 


7 feet 


8 feet 


9 feet 


10 feet 


AC 

Lb. 


18 
18 
20 
23 
24 
26 


.065 
.049 
.035 
.028 
.022 
.018 


2.61 
1,97 
1.40 
1.12 
.88 
.72 


8.28 
2.48 
1.76 
1.41 
1.11 
.91 


365 
275 
196 
156 
123 
101 


358 
270 
192 
154 
121 
99 


353 
267 
190 
152 
119 
97 


350 
264 

188 
150 
118 
97 


348 
262 
186 
149 
117 
96 


346 
261 
185 
148 
117 
95 


2.95 
2.31 
1.74 
1.46 
1.22 
1.06 



LAYING CORRUGATED ROOFING 

When laying corrugated iron on wood sheathing use galvanized 
iron nails and lead washers. The advantage in using lead washers is 
that they make a tight joint and prevent leaking and rusting at the nail 
hole; the washer being soft it easily shapes itself to any curve. In Fig. 
233 is shown how these washers are used; A shows the full size nail 




Fig. 233. 

and washer. When laying, commence at the left hand corner of the 
eave and end of the building. Continue laying to the ridge by lapping 
the second sheet over the first 4:inches,the left-hand edge being finished 
by means of a gable band A, formed as shown in Fig. 234, into which 
the corrugated sheet B is well bedded in roofer's cement C. When it 
is not desired to use this gable band the sheet must be well secured at 
the edge to keep the wind from raising the sheets from the roof in J, 
storm, as at A in Fig. 230, 



186 



SHEET METAL WORK 



Should the gable have a fire wall, then let the sheets A butt against 
the wall and flash with corrugated flashing as shown in Fig. 235, over 
which the regular cap or counter flashing is placed as explained in 

connection with Fig. 227. Should 
the ridge of the roof A butt 
against a wall, as shown at B in 
Fig. 230, then an end-wall flash- 
ing is used as is shown in Fig. 
236 which must also be capped, 
by either using cap flashing or 
allowing the corrugated siding 
to overlap this end-wall flashing 






Fig. 234. Fig. 235. 

as would be the case at B in Fig. 230. Now commence the 
second course at the eaves, giving one and one half corrugations for 
side lap, being careful that the side corrugations center each other 
exactly and nail with washers as shown in Fig. 237. Nail at every 

other corrugation at end laps, 
and at about every 6 inches at 
side laps, nailing through top 
of corrugation as shown in 
Fig - 236 - Fig. 237. Continue laying in 

this manner until the roof is covered. 

The same rule is to be observed in regard to laps and flashing if 
the corrugated iron were to be fastened to iron purlins, and the method 
of fastening to the iron frames would be accomplished as shown in Figs. 
238 to 240 inclusive. Assuming that 
steel structures are to be covered, as 
shown in Figs. 230 and 231, then let 
A in Fig. 238 be the iron rafter, B 
the cross angles on which the sheets D are laid, then by means 
of the clip or clamp C, which is made from hoop iron and bent around 
the angle B, the sheets are riveted in position. In Fig. 239 is shown 
another form of clamp, which is bent over the bottom of the angle iron. 



Fig. 237. 



SHEET METAL WORK 



187 



Fig. 240 shows still another method, where the clamp F is riveted to the 
sheet B at E, then turned around the angle A at D. To avoid having 
the storm drive in between the corrugated opening at the eaves, cor- 
rugated wood filler is used as shown in Fig. 241. This keeps out the 






Fig. 240. 



Fig. 238. Fig. 239. 

snow and sleet. On iron framing this is made of pressed metal. 
Another form of corrugated iron roofing is shown in Fig. 242. This is 
put down with cleats in a manner similar to standing-seam roofing. 

If there are hips on the roof, the corrugated iron should be care- 
fully cut and the hip covered 
with sheet lead. This is best 
done by having a wooden cove 
or filler placed on the hip, 
against which the roofing butts. 
Sheet lead is then formed over 
this wooden core and into the 
corrugations, and fastened by 
means of wood screws through the lead cap into the wooden core. 
The lead being soft, it can be worked into any desired shape. 
When a valley occurs in a hipped roof, form from plain sheet iron 
a valley as shown in Fig. 243, being sure to give it two coats of paint 

before laying, and make 



it from 24-inch wide 
sheets, bending up 12 
inches on each side. 
Fit it in the valley, and 

cut the corrugated iron to fit the required angle. Then lap the 

corrugated iron over the valley from 6 to & inches. 

When a chimney is to be flashed, as shown in Fig. 244, use plain 

iron, bending up and flashing into the chimney joints, and allowing 



Fig. 241. 



188 



SHEET METAL WORK 



the flashing to turn up under the corrugated iron at the top about 12 
inches and over the corrugated iron at the bottom about the same 
distance. At the side the flashing should have the shape of the cor- 
rugated iron and receive a lap of about 8 inches, the entire flashing 




Fig. 242. 
being well bedded in roofer's cement. When a water-tight joint is 
required around a smoke stack, as shown in Fig. 245, the corrugated 
iron is first cut out as shown, then a flashing built around one half the 
upper part of the stack to keep the water from entering inside. This 

is best done by using heavy 
sheet lead and riveting it to 
the sheets, using strips of sim- 
ilar corrugated iron as a 
washer to avoid damaging the 
lead. Before riveting, the 
flashing must be well bedded 
in roofer's cement and then 
make a beveled angle of 
cement to make a good joint. 
After this upright flashing is 
in position a collar is set over 
the same and fastened to the 
stack by means of an iron ring 




Fig. 243. 



bolted and made tight as shown. Cement is used to make a water- 
tight joint around the stack. This construction gives room for the 
stack to sway and allows the heat to escape. 

Sometimes the end-wall flashing shown in Fig. 236 can be used 



SHEET METAL WORK 



189 



to good advantage in building the upright flashing in Fig. 245. Where 
the corrugated iron meets at the ridge, as at D and D in Figs. 230 and 




Fig. 244. 

231, a wooden core is placed in position as explained in connection with 
the hip ridge, and an angle ridge, pressed by dealers who furnish the 

^giiHii.,.r v — * . — -i 




Fig. 245. 
corrugated iron, is placed over the ridge as shown in Fig. 246. When 
a ridge roll is required, the shape shown in Fig. 247 is employed. 



190 



SHEET METAL WORK 



These ridges are fastened direct to the roof sheets by means of riveting 
or bolting. 

LAYING CORRUGATED SIDING 

Before putting on any corrugated siding or clapboarding, as 
shown in Fig. 248, a finish is usually made at the eaves by means of a 




Fig. 246. 

hanging gutter or a plain cornice, shown in Fig. 249, which is fastened 
to the projecting wooden or iron rafters. This method is generally 
used on elevators, mills, factories, barns, etc., where corrugated iron, 
crimped iron or clapboards are used for either roofing or siding. This 




Fig. 247. 



style of cornice covers the eaves and gable projections, so as to make 
the building entirely ironclad. When laying the siding commence 
at the left hand corner, laying the courses from base to cornice, giving 
the sheets a lap of two inches as the ends and one and one half corruga- 




Fig. 248. 

tions at the sides. Nail side laps every 6 inches and end laps at every 
other corrugation, driving the nails as shown in Fig. 250. 

Where the sheets must be fastened to iron framing use the same 
method as explained in connection with Figs. 238, 239 and 240. In 
this case, instead of nailing the sheets, they would be riveted. If siding 
is put on the wooden studding care should be taken to space the stud- 
ding the same distance apart as the laying width of the iron used. In 



SHEET METAL WORK 



191 



this case pieces of studding should be placed between the uprights at 
the end of each sheet to nail the laps. When covering grain elevators 




Fig. 249. 

it is necessary to use swinging scaffolds. Commence at the base and 
carry up the course to the eave, the length of the scaffold. Commence 
at the left hand and give the sheets a lap of one corrugation on the side 
and a two-inch lap at the end. 



Fig. 250. 



Nail or rivet in every corru- 
gation 3 inches from the lower 
end of the sheet; this allows 
for settling of the building. 

When any structure is to 
be covered on two or more 
sides, corner casings made of 
flat iron are employed, of a 
shape similar to that shown at 
B, Fig. 251. It will be seen 
that a rabbet is bent on both 
sides a and b to admit the lg ' 

siding. This makes a neat finish on the outside and hides the 
rough edges of the siding. If a window opening is to have 
casings a jamb is used as shown at A, Fig. 251, which has a similar rab- 
bet at a to receive the siding, and a square bend at b to nail against the 
frame. In Fig. 252 is shown the cap of a window or opening. It is 




192 



SHEET METAL WORK 



bent so that a is nailed to the window or other frame at the bottom, 
while b forms a flashing over which the siding will set. Fig. 253 shows 
the sill of a window, which has a rabbet at a, in which the siding is 





Fig. 252. Fig. 253. 

slipped ; then b forms a drip, and any water coming over the sill passes 
over the siding without danger of leaks; c is nailed in white lead to the 
window frame. 

Another use to which corrugated iron is put is to cover sheds and 
awnings. Sheets laid on wood are nailed in the usual manner, while 
sheets laid on angle iron construction are fastened as explained in the 




Fig. 254. 
preceding sections. In Fig. 254 is shown an awning over a store laid 
on angle iron supports. In work of this kind, to make a neat appear- 
ance, the sheets are curved to conform to the iron bracket A. 



CORNICE OVER BRICK BAY* 



An elevation and plan of a brick bay are shown in the illustration, the 
sides of which are 8 inches, 3 feet 2 inches and 5 feet 10 inches wide. Laps 
or flanges for soldering are to be allowed on the 3 feet 2 inch pieces and no laps 
on the 8 inch and 5 feet 10 inch pieces. The lookouts or iron braces are indi- 
cated in the plan by the heavy dashes making a total of 9 required. 

After the detail section is drawn and knowing the angle of the bay in plan, 
the angle is placed as shown by ABC, being careful to place CB on a line drawr 
vertically from 3-4 in the section. The miter line is then drawn as shown by 
BD, the section divided into equal spaces, and vertical lines dropped to the 
miter line BD as shown. At right angles to BC the girth of the section is 
drawn as shown by similar figures from 1 to 26, through which points at righjf- 
angles to 1-26, lines are drawn and intersected by similar numbered lines 
drawn from the miter line BD at right angles to BC, thus obtaining the upper 
miter cut shown. Now using this miter cut in practice, make the distance 
from either points 25 or 24 (which represents the line of the wall) equal to 
8 inches, 3 feet 2 inches and 5 feet 10 inches. The 3 feet 2 inches and 5 fee* 
10 inches have opposite miter cuts as shown. 

As will be seen by the plan, two eight inch pieces will be required, one 
right and one left and two 3 feet 2 inch and one 5 feet 10 inch pieces. Nine 
iron lookouts will be required formed to the shape shown in the detail section* 
where holes are punched for bolting as there indicated. 



* The illustration referred to will be found on the back of this page. 



SHEET METAL WORK 

PART IV 



CORNICE WORK 

There is no trade in the building line to-day which has made such 
rapid progress as that of Sheet-Metal Cornice, or Architectural Sheet- 
Metal Work. It is not very long since the general scope of this branch 
of craftsmanship merely represented a tin-shop business on a large 
scale. But as things are to-day, this is changed. From an enlarged 
tin-shop business., sheet-metal cornice work, including under that title 
every branch of architectural sheet-metal work, has become one of the 
substantial industries of the country, comparing favorably with almost 
any other mechanical branch in the building trades. Nor is this work 
confined to the larger cities. In the smaller towns is shown the prog- 
ress of architectural sheet-metal work in the erection of entire building 
fronts constructed from sheet metal. 

CONSTRUCTION 

Sheet-metal cornices have heretofore, in a great measure, been 
duplications of the designs commonly employed in wood, which, in 
turn, with minor modifications, were imitations of stone. 

With the marked advancement of this industry, however, this 
need no longer be the case. A sheet-metal cornice is not now imita- 
tive. It possesses a variety and beauty peculiarly its own. No pat- 
tern is too complex or too difficult. Designs are satisfactorily executed 
in sheet metal which are impossible to produce in any other material. 
By the free and judicious application of pressed metal ornaments, a 
product is obtained that equals carved work. For boldness of figure, 
sharp and clean-cut lines, sheet-metal work takes the lead of all com- 
petitors. 

In order that there may be no misunderstanding as to the various 
parts contained in what the sheet-metal worker ; calls a "cornice," 
Fig. 255 has been prepared, which gives the names of all the members 
in the "entablature" — the architectural name for what in the shop is 



191 



SHEET METAL WORK 



known as the cornice. The term "entablature" is seldom heard 
among mechanics, a very general use of the word "cornice" having 
supplanted it in the common language of business. 

An entablature consists of three principal parts — the cornice, the 
frieze, and the architrave. A glance at the illustration will serve to 
show the relation that each bears to the others. Among mechanics 
the shop term for architrave is foot-moulding; for frieze, panel; and for 



T & ~' 




J QUARTER ROUND 



.£ 



STILE 



COVE 



PANEL 



8 V PANEL MOULD" 



I 

4- 

i 

DC 



"=> 



T — * — So 

-/DENTIL MOULD n.O 

\ L - 



WASH 



h 



FILLET 

A J QUARTER ROUND 



s 



t I 

! i 

.X— x.£FEL 



7 



FASCIA 



FASCIA 



] 



T 



I-? 

O _> 



_£. 



Fig. 255. 
the subdivisions of the cornice, dentil course, modillion coi*r«v f bed- 
mould, and crown-wwuld. In the modillion course, are the moditdon- 
band and modillion-mould; while in the dentil course are the dentil- 
band and dentil-mould. Drips are shown at the bottom of (he crown- 
and foot-mould fascias, and the ceiling under the crown mould is called 
the planceer. The edge at the top of the cornice is called a lock, and is 
used to lock the metal roofing into, when covering the top of the cor- 



SHEET METAL WORK 



195 



nice. In the panel, there are the panel proper, the panel-mould, and 
the stile. The side and front of the modillion are also shown. 

Fig. 256 shows the side and front view of what is known as a 
bracket. Large terminal brackets in 
cornices, which project beyond the 
mouldings, and against which the 
mouldings end, are called trusses, a 
front and a side view of which are 
shown in Fig. 257. A block placed 
above a common bracket against 
which the moulding ends, is called a 
stop block, a front and a side view of 
which are shown in Fig. 258. 




Fig. 256. 




FRONT 



SIDE 



Fig. 257. 



Fig. 259 is the front eleva- 
tion of a cornice, in which are 
shown the truss, the bracket, the 
modillion, the dentil, and the 
panel. It is sometimes the case, 
in the construction of a cornice, 
that a bracket or modillion is 
called for, whose front and sides 
are carved as shown in the front 
and side views in Fig. 260. In 
that case, the brackets are ob- 
tained from dealers in pressed 
ornaments, who make a specialty 
of this kind of work. The same 
applies to capitals which would 
be required for pilasters or col- 




umns, such as those shown in Figs. 261 and 262. The pilaster or 
column would be formed 
up in sheet metal, and the 
capital purchased and sol- 
dered in position. In Fig. 
263, A shows an inclined 
moulding, which, as far as 

general position is con- Flg - 258, 

cerned, would be the same as a gable moulding. 



FRONT 



SIDE 



196 



SHEET METAL WORK 



Raking mouldings are those which are inclined as in a gable 01 
pediment; but, inasmuch as to miter an inclined moulding (as A) into a 
horizontal moulding (as B and C), under certain conditions, necessi- 
tates a change of profile, the term "to rake," among sheet-metal work- 
ers, has come to mean "to change profiles" for the accomplishment of 




FRONT ELEVATION 

Fig. 259. 

such a miter. Hence the term "raked moulding" means one whose 
profile has been changed to admit of mitering. 

The term miter, in common usage, designates a joint in a mould- 
ing at any angle. 

Drawings form a very important part in sheet-metal architectural 




FRONT ELEVATION 



SIDE ELEVATION 



Fig. 260. 



work. An elevation is a geometrical projection of a building or other 
object, on a plane perpendicular to the horizon — as, for example, 
Figs. 259 and 263. Elevations are ordinarily drawn to a scale of \ or 



SHEET METAL WORK 



\ inch to the foot. A sectional drawing shows a view of a building or 
other object as it would appear if cut in two at a given vertical line — 
as, for example, Fig. 255. Detail drawings are ordinarily full size, and 




SECTION 
ON 



-_. S 




Fig. 261. 



Fig. 262. 



are often called working drawings. Tracings are duplicate drawings, 
made by tracing upon transparent cloth or paper placed over the orig- 




Fig. 263. 

inal drawing. Many other terms might be introduced here; but 
enough, we believe, hare been presented to give the student the leading 
general points. 



198 



SHEET METAL WORK 



A few words are necessary on the subject of fastening the cornice 
to the wall. 

Sheet-metal cornices are made of such a wide range of sizes, and 
are required to be placed in so many different locations, that the 
methods of construction, when wooden lookouts are employed and 




Fig. 264. 

when the cornice is put together at the building in parts, are worthy of 
the most careful study. The general order of procedure in putting 
up, is as follows: 

The foot-moulding or architrave a b (Fig. 264) is set upon the 
wall finished up to /, the drip a being drawn tight against the wall. 
The brickwork is then carried up, and the lookout A placed in position, 
the wall being carried up a few courses higher to hold the lookout in 
position. A board B is then nailed on top of the lookouts (which 
should be placed about three feet apart) ; and on this the flange of the 
foot-mould b is fastened. The frieze or panel b c is now placed into 
the lock B, which is closed and soldered; when the lookout C and the 
board D are placed in their proper positions, as before described. 



SHEET METAL WORK 



199 



The planceer and bed-mould c d are now locked and soldered at 
D, and the lookout E placed in position, with a board F placed under 
the lookouts the entire length of the cornice; onto this board the plan- 
ceer is fastened. Having the proper measurements, the framer now 
constructs his lookouts or brackets G H I E, fastening to the beam at 
T, when the crown-mould d e is fastened to the planceer, through the 
flange of the drip at d, and at the top at e. The joints between lengths 
of mouldings, are made by lapping, riveting, or bolting, care being 
taken that they are joined so neatly as 
to hide all indications of a seam when 
finished and viewed from a short 
distance. 

If brackets or modillions are to 
be placed in position, they are riveted 
or bolted in position; or sometimes the 
back of the cornice is blocked out 
with wood, and the brackets screwed 
in position through their flanges. 

While a galvanized-iron cornice 
thus constructed on wooden lookouts 
will resist fire for a long time, a strict- 
ly fireproof cornice is obtained only 
by the use of metal for supports and 
fastenings, to the entire exclusion of 
wood. This fireproof method of con- 
struction is shown in Fig. 265. In- 
stead of putting up in parts on the building, the cornice is con- 
structed in one piece in the shop or upon the ground, and hoisted 
to the top of the wall in long lengths easily handled. A drip a is used 
at the bottom of the foot-mould, and the joints made in the way in- 
dicated at b and c, with a lock at d. Band iron supports and braces 
are used, formed to the general contour of the parts as shown by A B 
C, and bolted direct to the cornice, as shown, before hoisting. 

When the cornice sets on the wall as at C, anchors are fastened 
to the main brace, as at D and E, with an end bent up or down for 
fastening. If the cornice sets perfectly plumb, the mason carries up 
iis wall, which holds the cornice in a firm position. The top and 
back are then framed in the usual manner and covered by the metal 




Fig. 265. 



200 SHEET METAL WORK 

roofer. In constructing cornices in this manner, the mouldings are 
run through solid, behind all brackets and modillions. The brackets 
and modillions are attached by means of riveting through outside 
flanges. 

SHOP TOOLS 

One of the most important tools in cornice or architectural sheet- 
metal working shop is the brake. On those operated by hand, sheets 
are bent up to 8 feet in one continuous length. In the larger shops, 
power presses or brakes are used, in which sheets are formed up to 10 
feet in length, the press being so constructed that they will form ogees, 
squares, or acute bends in one operation. 

Large 8- or 10-feet squaring shears also form an important ad- 
dition to the shop, and are operated by foot or power. 

When cornices are constructed where the planceer or frieze is very 
wide, it is usual to put crimped metal in, to avoid the waves and buck- 
les showing in the flat surface; for this purpose the crimping machine 
is used. 

In preparing the iron braces for use in the construction of fire- 
proof cornices, a punching machine and slitting shears are used for 
cutting the band iron and punching holes in it to admit the bolts. 
While braces are sometimes bent in a vise, a small machine known as a 
brace bender is of great value in the shop. In large fireproof building 
constructions, it is necessary that all doors, window frames, and even 
sashes be covered with metal, and made in so neat a manner that, 
when painted and grained, no differences will be apparent to indicate 
whether the material is wood or metal, the smallest bends down to I 
inch being obtained. This, of course, cannot be done on the brakes 
just mentioned, but is done by means of the draw-bench, which is con- 
structed in lengths up to 20 feet and longer, operated by means of an 
endless chain, and capable of drawing the sheet metal over any shaped 
wood mould as tightly as if it were cast in one piece. The smaller 
tools in the shop are similar to those referred to on page 4 of 
this volume. 

METHOD EMPLOYED FOR OBTAINING PATTERNS 

The principles applied to cylinder developments, as explained 
on page 5 and following in the treatment of the Parallel- 
Line method of development, are also applicable for obtaining 



SHEET METAL WORK 



201 




the patterns for any moulding where all members run parallel; for it 
makes no difference what profile is employed, so long as the lines run 
parallel to one another, the parallel-line method is used. While 
this method is chiefly employed in cornice work, other problems will 
arise, in which the "Radial-Line" and the "Triangulation" methods 
will be of service. 

The term generally used in the shop for pattern cutting on cornice 
work is miter cutting. To illustrate, suppose two pieces of mouldings 
are to be joined together at 
angle of 90°, as shown in Fig. 
266. The first step necessary 
would be to bisect the given 
angle and obtain the miter- 
line and cut each piece so that 
they would miter together. If a Fi S- 266 - 

carpenter had to make a joint of this kind, he would place his moulding 
in the miter-box, and cut one piece right and one piece left at an angle 
of 45°, and he would be careful to hold the moulding in its proper po- 
sition before sawing; or else he may, instead of having a return miter 

as shown, have a face miter as in 
a picture frame, shown in Fig. 
267. The sheet-metal cornice- 
maker cannot, after his moulding 
is formed, place it in the miter- 
box to cut the miter, but must 
lay it out — or, in other words, 
develop it — on a flat surface or 
sheet of metal. He must also be 



Y 



Fig. 267. 



careful to place the profile in its proper position with the miter- 
line; or else, instead of having a return miter as shown in Fig. 266, he 
will have a face miter as shown in Fig. 267. If he lays out his work 
correctly, he can then cut two pieces, form one right and the other left, 
when a miter will result between the two pieces of moulding and will 
look as shown in Fig. 266. If, however, a face miter is desired, as 
shown in Fig. 267, which is used when miters are desired for panels 
and other purposes, the method of laying them out will be explained as 
we proceed. The same principles required for developing Figs. 266 
and 267 are used, whether the mouldings are mitered at angles of 90° 



202 



SHEET METAL WORK 



or otherwise. The method of raking the mouldings — or, in other 
words, changing their profile to admit the mitering of some other 
moulding at various angles — will also be thoroughly explained as we 
proceed. 

VARIOUS SHAPES OF MOULDINGS 

The style of mouldings arising in the cornice shop are chiefly 

Roman, and are obtained by using the arcs of a circle. In some cases, 

Greek mouldings are used, the outlines of which follow the curves 

of conic sections; but the majority of shapes are arcs of circles. In 





Fig. 268. Fig. 269. 

Figs. 268 to 272 inclusive, the student is given a few simple lessons on 
Roman mouldings, which should be carefully followed. As all pat- 
tern-cutters are required to draw their full-size details in the shop from 
small-scale drawings furnished by the architect, it follows that they 
must understand how to draw the moulds with skill and ease; other- 





Fig. 270. Fig. 271. 

wise freehand curves are made, which lack proportion and beauty. 

In Fig. 268, A shows the mould known as the cyma recta, known 
in the shop as the ogee, which is drawn as follows : 

Complete a square abed; draw the two diagonals a c and b d, 
intersecting each other at e. Through e, draw a horizontal line inter- 
secting ad at / and b c at h. Then, with / and h as centers, draw re- 
spectively the two quarter-circles a e and e c. 



SHEET METAL WORK 



202 



In Fig. 269, B shows the cyma reversa, known in the shop as the 
ogee, reversed. Complete a square abed, and draw the two diagonals 
b d and a c intersecting at e; through e, draw a vertical line intersecting 
a b at / and cdaih, which points are the respective centers for the arcs 
a e and e c. 

C in Fig. 270 shows the cavetto, called the cove in the shop, which 
is drawn by completing a square abed. Draw 
the diagonal b d at 45°, which proves the 
square; and, using d as a center, draw the 
quarter-circle a c. 

In Fig. 271, D represents the ovolo or 
echinus, known in the shop as the quarter- 
round, which is constructed similarly to C in 
Fig. 270, with the exception that b in Fig. 271 
is used to obtain the curve ac. 

E in Fig. 272 is known as the torus, known in the shop as a bead- 
mould. A given distance a b is bisected, thus obtaining c, which is the 
center with which to describe the semicircle a b. 

All of these profiles should be drawn by the student to any de- 
sired scale for practice. In preparing mouldings from sheet metal, 




Fig. 272. 





ooioiaociiciiici 



!5> 



Fig. 273. 

it is sometimes required that enrichments are added in the ogee, cove, 
and bead. In that case the mould must be bent to receive these en- 
richments, which are usually obtained from dealers in stamped or 
pressed sheet-metal work. Thus, in Fig. 273, F represents a front 
view of a crown mould whose ogee is enriched, the section of the en- 



204 



SHEET METAL WORK 



riehment being indicated by a b in the section, in which the dotted line 
d c shows the body of the sheet-metal moulding bent to receive the 
pressed work. In Fig 274, H represents part of a bed-mould in which 




Fig. 274. 

egg-and-dart enrichments are placed. In this case the body of the 
mould is bent as shown by c d in the section, after which the egg-and- 
dart is soldered or riveted in position. J in Fig. 275 represents part 




Fig. 275. 

of a foot-mould on which an enriched bead is fastened. The body of 
the mould would be formed as indicated by c in the section, and the 
bead a b fastened to it. This same general method is employed, no 
matter what shape the pressed work has. 

PRACTICAL MITER CUTTING 

Under this heading come the practical shop problems. The prob- 
lems which will follow should be drawn to any desired scale by the 
student, developed, and bent from stiff cardboard to prove the accu- 
racy of the pattern. If the student cannot use the small brake in the 
shop and test his patterns cut from metal, he can use the dull blade of 
a table knife, over which the bends can be made, when using cardboard 
patterns. This at once proves interesting and instructive not 
only from the purely manipulation standpoint but also from the 
fact that, in this manner, a check on the accuracy of one's work 



SHEET METAL WORK 



205 



will be obtained. While the problems selected cannot possibly 
cover the whole field, they have been chosen with care so as to 
illustrate sufficiently the basic principles involved. 

The first problem will be to obtain the development of a square 
return miter, such as would occur when a moulding had to return 
around the corner of a building, as shown in Fig. 276. In Fig. 277 
are shown two methods of ob- 
taining the pattern. The first 
method which will be described 
is the "long" method, in which 
are set forth all the principles 
applicable to obtaining pat- 
terns for mouldings, no matter 
what angle the plan may have. 




Fig. 276. 
The second method is the "short' 



ELEVATION 




Fig. 277. 



206 SHEET METAL WORK 

rule generally employed in the shop, which, however, can be used only 
when the angle H G F in plan is 90°, or a right angle. 

To obtain the pattern by the first method, proceed as follows: 
First, draw the elevation of the mould as shown by 1, B, A, 11, drawing 
the coves by the rule previously given. Divide the curves into equal 
spaces; and number these, including the corners of the fillets as shown 
by the small figures 1 to 1 1. In its proper position below the elevation, 
draw the soffit plan as shown by C D E F G H. Bisect the angle H G 
F by the line G D, which is drawn at an angle of 45°. From the va- 
rious intersections in the elevation, drop lines intersecting the miter-line 
as shown. At right angles to H G, draw the stretchout line 1' 11', 
upon which place the stretchout of the mould 1 11 in elevation, as 
shown by similar figures on the line 1' 11'. At right angles to 1' 
11', and from the numbered points thereon, draw lines, which intersect 
by lines drawn at right angles to H G from similarly numbered inter- 
sections on the miter-line G D. Trace a line through the intersections 




Fig. 278. 
thus obtained, as shown by J G. Then will 1' G J 11' be the desired 
pattern. This gives the pattern by using the miter-line in plan. 

In developing the pattern by the short method, on the other hand, 
the plan is not required. At right angles to 1 B in elevation, draw the 
stretchout line 1" 11", upon which place the stretchout of the profile 
1 11 in elevation, as shown by similar figures on 1" 11", at right 
angles to which draw lines through the numbered points as shown, 
which intersect by lines drawn at right angles to 1 B from similarly 
numbered intersections in the profile in elevation. Trace a line through 
points thus obtained, as shown by G K. Then will G 1" 11" K be 
similar to J G 1' 11' obtained from the plan. 



SHEET METAL WORK 



207 



In Fig. 278 is shown a horizontal moulding butting against a 
plane surface oblique in elevation. A miter cut of this kind would 
be required when the return moulding of a dormer window would butt 
against a mansard or other pitched roof. In this case we assume A 
to be the return butting against the pitched roof B. The method of 



PATTERN 




SECTION 



Fig. 279. 

obtaining a pattern of this kind is shown in Fig. 279. Let A B C D 
represent the elevation of the return, A D representing the pitch of the 
roof. In its proper position as shown, draw the section 111, which 
divide into equal spaces as shown, and from which, parallel to A B, 
draw lines intersecting the slant line A D from 1 to 11, as shown. At 
right angles to AB erect the stretchout line 1' 11', upon which place 
the stretchout of the section as shown by similar figures on 1' 11'. 
At right angles to 1' 11', and through the numbered points thereon, 
draw lines, which intersect by lines drawn at right angles to A B from 
similarly numbered intersections on the slant line A D. Through 



208 



SHEET METAL WORK 



the various intersections thus obtained, draw E F. Then will E F 
11' V be the desired pattern. 

It is sometimes the case that the roof against which the moulding 
butts, has a curved surface either concave or convex, as shown by B C 
in Fig. 280, which surface is convex. Complete the elevation of the 
moulding, as D E; and in its proper position draw the section 1 9, 
which divide into equal spaces as shown by the small figures, from 
which draw horizontal lines until they intersect the curved line B C, 
which is struck from the center point A. At right angles to the line 
of the moulding erect the line 1' 9', upon which place the stretchout 



PATTERN 



/> 



Mr 




SECTION 



Fig. 280. 
of the section, as shown by the figures on the stretchout line. Through 
the numbered points, at right angles to 1' 9', draw lines, which 
intersect by lines drawn at right angles to 2 D from similarly numbered 
intersections on the curve B C, thus resulting in the intersections I" to 
9" in the pattern, as shown. The arcs 2" 3" and 7" 8" are simply repro- 
ductions of the arcs 2 3 and 7 9 on B C. These arcs can be 
traced by any convenient method; or, if the radius A C is not too long- 
to make it inconvenient to use, the arcs in the pattern may be obtained 
as follows: Using A C as radius, and V and 8" as centers, describe 
arcs intersecting each other at A 1 ; in similar manner, using 2" and 3" 
as centers, and with the same radius, describe arcs intersecting each 



SHEET METAL WORK 



209 



other at A 2 . With the same radius, and with A 1 and A 2 as centers, 
draw the arcs 8" 7" and 3" 2" respectively. Trace a line through 
the other various intersections as shown. Then will V I" 9" 9' be the 
desired pattern. 

In Fig. 281 is shown an elevation of an oblong or rectangular 
panel for which a miter-cut is desired on the line a b — known as a 
"panel" or "face" miter. The 
rule to apply in obtaining this 
pattern is shown in Fig. 282. 
A shows the part elevation of 
the panel; a b and c d, the 
miter-lines drawn at angles of 
45°. In its proper position 
with the lines of the mould- 
ing, draw the profile B, the 
curve or mould of which divide 
into equal spaces, as shown 
by the figures 1 to 7 ; and from 
the points thus obtained, par- 
allel to 1 b, draw lines inter- 



6 




Fig. 281. Fig. 282. 

secting the miter-line a b as shown. From these intersections, par- 
allel to b d, draw lines intersecting also c d. At right angles to b d 
draw the stretchout line V T, upon which place the stretchout of the 
profile B. At right angles to 1' 7, and through the numbered 
points of division, draw lines, which intersect by lines drawn at right 
angles to b d from similarly numbered intersections on the miter- 
lines a b and c d. Trace lines through the various points of inter- 
section in the pattern as shown. Then will C D E F be the required 
cut for the ends of the panel. 

The same miter-cuts would be employed for the long side a c & 



210 



SHEET METAL WORK 



Fig. 281, it being necessary only to make D E in Fig. 282 that length 
when laying out the patttern on the sheet metal. 

Where the miter-cut is required for a panel whose angles are other 
than right angles, as, for example, a triangular panel as shown in Fig. 
283, then proceed as shown in Fig. 284. First draw the elevation of 
the triangular panel as shown by A B C, the three sides in the case 
being equal. Bisect each of the angles A, B, and C, thus obtaining the 
miter-lines A c, B b, and C a. In line with the elevation, place in its 
proper position the profile 
E, which divide into equal 
spaces as shown; and from 
the numbered division 
points, parallel to A C, draw 
lines cutting the miter-line 
C a. From these intersec- 
tions, parallel to C B, draw 
lines intersecting the miter- 
line b B. At right angles to 
C B draw the stretchout line 
1' 7', upon which place the 



ELEVATION 





Fig. 283. 



Fig. 284. 



stretchout of the profile E. Through the numbered points of divi- 
sion and at right angles to 1' 7', draw lines as shown, which intersect 
by lines drawn at right angles to C B from intersections of similar 
numbers on the miter-lines a C and b B. Through the points thus 
obtained, trace the pattern F G H I. 

It makes no difference what shape or angle the panel may have; 
the principles above explained are applicable to any case. 

In ornamental cornice work, it often happens that tapering mould- 
ed panels are used, a plan and elevation of which are shown in Fig. 285. 



SHEET METAL WORK 



211 



By referring to the plan, it will be seen that the four parts b a, a b f , b' a', 
and a' b are symmetrical; therefore, in practice, it is necessary only to 
draw the one-quarter plan, as shown in Fig. 286, and omit the eleva- 
tion, since the height d e (Fig. 285) is known. Thus, in Fig. 286, draw 
the quarter-plan of the panel, no matter what is its shape, as shown 




Fig. 285. 

by a 1 5 6 9. Divide the curves from 1 5 and 6 9 into equa- 
spaces, indicated respectively by 1, 2, 3, 4, and 5, and 6, 7, 8, and 9. 
From these points, draw lines to the apex a. As the pattern will be de- 
veloped by triangulation, a set of triangles will be required, as shown in 




Fig. 286. 

Fig. 287, for which proceed as follows: Draw any horizontal line, as 
a 1 ; and from a erect the perpendicular a a' equal to the height the 
panel is to have. Now take the lengths of the various lines in Fig. 286 
from a to 1, a to 2, a to 3, etc., to a to 9, and place them on the line a 1 in 
Fig. 287, as shown by similar numbers. Then using as radii the various 



212 



SHEET METAL WORK 



lengths a! 1, a' 2, a' 3, etc., to a' 9, and with any point, as a' in Fig. 
288 as center, describe the various arcs shown from 1 to 9. From any 
point on the arc 1 draw a line to a'. Set the dividers equal to the 

spaces contained in the 
curve 1 5 in Fig. 286; and, 
starting from 1 in Fig. 288 
step from one arc to an- 
other having similar num- 
bers, as shown from 1 to 5. 
In similar manner, take the 
distance from 5 to 6 and 
the spaces in the curve 6 9 




Fig. 287. 




Fig. 288. 



in Fig. 286, and place them on corresponding arcs in Fig. 288, step- 
ping from one arc to the other, resulting in the points 5 to 9. Trace 
a line through the points 
thus obtained. Then 
will a' 1 5 6 9 a' be the 
quarter-pattern, which 
can be joined in one- 
half or whole pattern as 
desired. 

In Fig. 289 is shown 
a perspective of a mould- 
ing which miters at an 
angle other than a right angle. This occurs when a moulding is 
required for over a bay window or other structure whose angles vary. 

The rule given in Fig. 290 is applicable 
to any angle or profile. First draw a 
section or an elevation of the moulding 
as shown by A B 14 1. Directly below 
the moulding, from its extreme point, 
as 2 3, draw a plan of the desired 
angle as shown by C 2 D. Bisect this 
angle by using 2 as center and, with 
any radius, describing an arc meeting 
the sides of the angle at C and E. With the same or any other radius, 
and with C and E as centers, describe arcs intersecting each other in F. 
From the corner 2, draw a line through F. Then will 2 H be the 




Fig. 289. 



SHEET METAL WORK 



213 



miter-line, or the line bisecting the angle C 2 D. Now divide the 
profile 1 14 into equal spaces as shown by the figures, and from the 
points thus obtained drop vertical lines intersecting the miter-line 2 



2 i 



4[5 



14 13 



glO 



l i 
I I 

I • 



12 

13 




Fig. 290. 

H in plan from 1 to 14 as shown- 
At right angles to C 2, draw the 
line J K, upon which place the 
stretchout of the profile in elevation 
as shown by similar figures on the 
stretchout line, through which drop 
lines perpendicular to J K, which 
intersect with lines drawn parallel 
to J K from similarly numbered 
s ' l points of intersection on the miter- 

line 2 H. Trace a line as shown by L M, which is the miter-cut 
desired. 

When two mouldings having different profiles are required to 
miter together as shown in Fig. 291, where C miters at right angles 




214 



SHEET METAL WORK 



with D, two distinct operations are necessary, which are clearly shown 
in Figs. 292 and 293. The first operation is shown in Fig. 292, in 
which C represents the elevation of an ogee moulding which is to 
miter at right angles with a moulding of different profile as shown at D. 

Divide the profile C into equal 
2 spaces, from which points draw 
horizontal lines intersecting the 
moulding D from V to 10'. At 
right angles to the line of the 
moulding C, draw the line A B, 
upon which place the stretchout 
of the profile C as shown by simi- 
lar figures on A B. At right 
angles to A B, and through the 









PATTFRN FOR C 
Fig. 292. 

points indicated by the figures, 
draw lines, which intersect with 
lines drawn parallel to A B from 
similarly numbered intersections 
in the profile D. Trace a line 
through the points thus obtained, 
as shown by E H. Then will E 
F G H be the pattern for C in 
elevation. 

To obtain the pattern for D, 
draw the elevation of D (Fig. 293), which is to miter at right 
angles with a moulding whose profile is C. Proceed in precisely 
the same manner as explained in connection with Fig. 292. Divide 
the profile D in Fig. 293 into equal parts, as shown, from 
which draw horizontal lines cutting the profile C. At right angles 



Fig. 293. 



SHEET METAL WORK 



215 




Fig. 294. 



to the lines of the moulding D, draw the stretchout line A B, upon 
which place the stretchout of the profile D. At right angles to A B, 
and through the numbered points of division, draw lines as shown, 
which intersect by lines drawn parallel to A B from similarly numbered 
intersections in the profile C. Through these points of intersection 
draw F G. Then will E F G H be the desired pattern for D. 

It should be understood that when the patterns in Figs. 292 and 
293 are formed and joined together, they will form an inside miter, as 
is shown in Fig. 291. 
If, however, an outside 
miter were required, it 
would be necessary only 
to use the reverse cuts of 
the patterns in Figs. 292 
and 293, as shown by E J 
H in Fig. 292 for the 
mould C, and F J G in 
Fig. 293 for the mould D. 

When joining a 
curved moulding with a straight moulding in either plan or eleva- 
tion even though the curved or straight mouldings each have the 
same profile, it is necessary to establish the true miter-line before 
the pattern can be correctly developed, an example being given in 
Fig. 294, which shows an elevation of a curved moulding which 
is intersected by the horizontal mouldings A B. The method of ob- 
taining this miter-line, also the pattern for the horizontal pieces, is 
clearly shown in Fig. 295. First draw the profile which the horizontal 
moulding is to have, as 1 10. Let the distance 9 B be established. 
Then, with C on the center line as center, and A C as radius, describe 
the arc B A. From any point on the line 9 B, as a, erect the vertical 
line a b. Through the various divisions in the profile 1 10, draw 
horizontal lines intersecting the vertical line a b from 1 to 10 as shown. 
From the center C, draw any radial line, as C d, cutting the arc B A at e. 
Now take the various divisions on a b, and place them from e to d as 
shown by points 1' to 10'. Then, using C as center, with radii deter- 
mined by the various points on e d, draw arcs intersecting horizontal 
lines of similar numbers drawn through the divisions on a b. Through 



216 



SHEET METAL WORK 



these points of intersection, draw the miter-line shown. The student 
will note that this line is irregular. 

Having obtained the miter-line, the pattern is obtained for the 
horizontal moulding by drawing the stretchout line E F at right angles 
to 9 B. On E F lay off the stretchout of the profile 1 10; and 
through the numbered points and at right angles to E F, draw hori- 
zontal lines, which intersect with lines drawn at right angles to 9 B 

from similarly numbered in- 
tersections in the miter-line 
determined by horizontal lines 
already drawn through the 
vertical line a b. Trace a line 
through the points thus ob- 
tained, as shown by H I J K, 
which is the desired pattern. 





Fig. 296. 

In Fig. 296 is shown a shaded view of a gable moulding intersect- 
ing a pilaster, the gable moulding B cutting against the vertical pilaster 
A, the joint-line being represented by a be. To obtain this joint-line, 
without which the pattern for the gable moulding cannot be developed, 
an operation in projection is required. This is explained in Fig. 297, 
in which BCD shows the plan of the pilaster shown in elevation by E. 
In its proper position in plan, place the profile of the gable moulding, 
as shown by A, which divide into equal spaces as shown by the figures 
1 to 8, through which draw horizontal lines intersecting the plan of the 
pilaster B C D as shown by similar figures. For convenience in pro- 



SHEET METAL WORK 



217 



jecting the various points, and to avoid a confusion of lines, number 
the intersections between the lines drawn from the profile A through 
the wash B 2, "7°", "4°", and "3°". At the desired point H in eleva- 
tion, draw the lower line of the gable moulding, as H F. Take a 
tracing of the profile A 
in plan, with all of the 
various intersections on 
same, and place it in 
elevation as shown by 
A 1 , placing the line 1 8 at 
right angles to H F. 
Through the various in- 
tersections 1, 7°, 4°, 3°, 
2,3,4,5,6,7, and 8 in 
A 1 , and parallel to F H, 
draw lines indefinitely, 
which intersect by lines 
drawn at right angles to 
C B in plan from sim- 
ilarly numbered intersec- 

tions in the pilaster C D 
B, thus obtaining the 
points of intersection l x 
to 8 X in elevation. 

For the pattern, pro- 
ceed as follows: At right 
angles to H F, draw the 
stretchout line J K, upon 
which place the stretch- 
out of the profile A or A 1 , 
with all the points of in- 
tersection on the wash 
1 2. At right angles to J K, and through the numbered points, draw 
lines as shown, which intersect by lines drawn at right angles to H 
F from similarly numbered intersections in the joint-line l x 8 X 
Through the points thus obtained, trace the miter-cut M N O. Then 
will L M N O P be the pattern for the gable moulding. 

In Fig. 298 are shown gable mouldings mitering upon a wash. The 




518 



SHEET METAL WORK 




mouldings A A intersect at any desired angle the wash B. In this case, 
as in the preceding problem, an operation in projection must be gone 
through, before the pattern can be obtained. This is clearly shown 

in Fig. 299. Draw the section of the 
horizontal moulding B 1 with the wash 

i-^^jg?' b ~^ s ^s ; nZZ? a b. From this section project lines, 

l J and draw the part elevation D C. 

Fig. 298. Knowing the bevel the gable is to 

have, draw C B, in this case the top line of the moulding. Draw a 
section of the gable mould, as A, which divide into equal parts as 
shown from 1 to 8; and through the point of division draw lines 
parallel to B C, indefinitely, as shown. Take a tracing of the profile 
A, and place it in section as shown by A 1 . Divide A into the same 

G 



TERN 




SECTION 



ELEVATION 
Fig. 299. 



number of spaces as A; and from the various divisions in A 1 drop 
vertical lines intersecting the wash a & as shown, from which points 
draw horizontal lines intersecting lines drawn parallel to B C 
through similarly numbered points in A, at 1° to 8°. Trace a line 
through these intersections as shown, which represents the miter-line 
or line of joint in elevation. 

For the pattern, draw any line, as E F, at right angles to B C, upon 
which place the stretchout of the profile A, as shown by similar figures 
on the stretchout line E F. Through the numbered points of division 
and at right angles to E F, draw lines as shown, which intersect by 



SHEET METAL WORK 



219 




Fig. 300. 



lines drawn at right angles to B C from similarly numbered intersec- 
tions on 1° 8° and on the vertical line B D. A line traced through 
points thus obtained, as shown by G H I J, will be the desired pattern. 

In Fig. 300 is shown a front view of a turret on which four gables 
are to be placed, as shown by A A; also the roofs 
over same, as shown by B B. The problem con- 
sists in obtaining the developments of the gable 
mouldings on a square turret. In developing 
this pattern, the half-elevation only is required, 
as shown in Fig. 301, in which first draw the 
center line E F; then establish the half-width of 
the turret, as C D, and draw the rake B C. At 
right angles to the line B C, and in its proper 
position as shown, draw the profile A, which 
divide into equal spaces as shown by the figures 
1 to 6, through which, parallel to B C, draw lines intersecting the 
center line F E as shown; and extend the lines below C, indefinitely. 
Now take a tracing of the profile A, and place it in position as 
shown by A 1 , being careful to have it spaced in the same number of 
divisions, as shown from 1 to 6, through which, parallel to D C, erect 
lines intersecting similarly numbered lines drawn through the profile 
A, thus obtaining the intersections 1° to 6°, through which a line is 
traced, which represents the line of joint at the lower end between 
the two gables. 

For the pattern, take a stretchout of A, and place it on the line 
J K drawn at right angles to B C, as shown by the figures 1 to 6 on J K. 
At right angles to J K, and through these points of division, draw lines, 
which intersect by lines drawn from similarly numbered intersections 
on F B and 1° 6°. Trace a line through the points thus obtained, 
as shown by F° B° C° 6°, which is the desired pattern, of which eight 
are required to complete the turret, four formed right and four left. 

If the roof shown by B in Fig. 300 is desired to be added to the 
pattern in Fig. 301, then, at right angles to F° 6°, draw the line F° F 1 
equal to F H in the half-elevation, and draw a line from P to 6° in the 
pattern. 

In Fig. 302 is shown front view of an angular pediment with hori- 
zontal returns at bottom A and top B. In this problem, as in others 
which will follow, a change of profile is necessary before the correct 



220 



SHEET METAL WORK 



pattern for the returns can be developed. In other words, a new pro- 
file must be developed from the given or normal profile before the pat- 
terns for the required parts can be developed. It should be under- 
stood that all given profiles are always divided into equal spaces; there- 
fore the modified profiles will contain unequal spaces, each one oi 




Fig. 301. 

which must be carried separately onto the stretchout line. Bearing 
this in mind, we shall proceed to obtain the modified or changed pro- 
files and patterns for the horizontal returns at top and foot of a gable 
moulding, as at B and A in Fig, 302, the given profile to be placed in the 
gable moulding C. In Fig. 303, let C represent the gable moulding 




SHEET METAL WORK 221 

placed at its proper angle with the horizontal moulding G H. Assum- 
ing that 6 X 6° is the proper angle, place the given profile A at right 
angles to the rake, as shown; and divide same into equal spaces as 
shown from 1 to 10, through which points, parallel to 6 X 6°, draw lines 
towards the top and bottom of the 
raking moulding. Assuming that the 
length 6 X 6° is correct, take a tracing 
of the profile A, and place it in a ver- 
tical position below at A 1 and above 
at A 2 , being careful to have the points 
6 and 6 in the profiles directly in a ver- Fi §- 303 - 

tical position below the points 6 X and 6°, as shown. From the va- 
rious intersections in the profiles A 1 and A 2 (which must contain the 
same number of spaces as the given profile A), erect vertical lines 
intersecting lines drawn through the profile A, as shown at the lower 
end from l x to 10 x , and at the upper end from 1° to 10°. Trace a line 
through the points thus obtained. Then will l x 10 x be the modified 
profile for the lower horizontal return, and 1° 10° the modified profile 
for the upper horizontal return. 

Note the difference in the shapes and spaces between these two 
modified profiles and the given profile A. It will be noticed that a 
portion of the gable moulding miters on the horizontal moulding G H 
from 6 X to 10'. 

For the pattern for the gable moulding, proceed as follows: At 
right angles to E F, draw the stretchout line J K, upon which place 
the stretchout of the given profile A, as shown by the figures 1 to 10 on 
J K. Through these figures, at right angles to J K, draw lines as 
shown, which intersect with lines drawn at right angles to E F from 
similarly numbered intersections in 1° 10° at the top and l x 6 X 
10' at the lower end. Trace a line through the intersections thus ob- 
tained. Then will L M N O be the pattern for C. 

For the pattern for the horizontal return at the top, draw a side 
view as shown at B, making P R the desired projection, and the profile 
1 10 on B, with its various intersections, an exact reproduction of 
1° 10° in the elevation. Extend the line R T as R S; and, starting 
from 10, lay off the stretchout of the profile in B as shown by the figures 
1 to 10 on R S, being careful to measure each space separately. At 
right angles to R S draw the usual measuring lines, which intersect 



222 



SHEET METAL WORK 



by lines drawn parallel to S R from similarly numbered points in the 
profile in B. Trace a line through points thus obtained. Then will 
U V 10 1 be the pattern for the return B. 

In similar manner, draw the side view of the lower horizontal 
return as shown at D, making the projection W 10 equal to P R 



— fy m ^ id jftMB 







— (V<Wfl<eN<0 o>2 X 



in B. The profile shown from 1 to 10 in D, with all its divisions, is 
to be an exact reproduction of the profile l x to 10 x in elevation. Extend 
the line "W X as X Y, upon which lay off the stretchout of the profile 
1 10 in D, being careful that each space is measured separately, 
as they are all unequal. Through the figures on X Y draw lines as 



SHEET METAL WORK 



223 



shown, which intersect by lines drawn parallel to W Y from the various 
intersections in the profile in the side D. A line traced through points 
thus obtained, as shown by Z V, will be the desired cut, and 1 Z 
V 10 the pattern for the return D. 

In Fig. 304 is shown a front view of a segmental pediment with 
upper and lower horizontal returns. 
This presents a problem of obtaining 
the pattern for horizontal returns at 
top and foot of a segmental pediment, 
shown respectively at A and B, the 
given profile to be placed in C. The Fl §- 304 - 

principles used in obtaining these patterns are similar to those 
in the preceding problem, the only difference being that the mould- 
ing is curved in elevation. In Fig. 305 the true method is clearly 
given. First draw the center line B D, through which draw the horizon- 





\e. 



-H 



&-- -— 

Fig. 305. 

tal line C C 1 . From the line C C 1 establish the height E; and with the 
desired center, as B, draw the arc E C intersecting the line C 1 C at C. 
In its proper position on a vertical line F G, parallel to D B, draw the 
given profile of the curved moulding as shown by A, which divide into 
equal spaces as shown from 1 to 10. Through these figures, at right 
angles to F G, draw lines intersecting the center line D B as shown. 



224 



SHEET METAL WORK 



Then, using B as center, with radii of various lengths corresponding 
to the various distances obtained from A, describe arcs as shown, ex- 
tending them indefinitely below the foot of the pediment. The point 
C or 6" being established, take a tracing of the profile A, with all the 
various points of intersection in same, and place it as shown by A 2 , 
being careful to have the point 6 in A 2 come directly below the point 
6" in elevation in a vertical position. Then, from the various inter- 
sections in A 2 erect vertical lines intersecting similarly numbered arcs 
drawn from the profile A. Trace a line as shown from 1" to 10", 
which is the modified profile for the foot of the curved moulding. 

Establish at pleasure the point 1' at the top, and take a tracing 
of the given profile A, placing it in a vertical position below 1', as 

shown by A 1 . From the various 
intersections in A 1 erect vertical 
lines intersecting similarly num- 
bered arcs as before. Through 
these intersections, shown from 
V to 10', trace the profile shown, 
which is the modified profile for 
the top return. 

The curved moulding shown 
in elevation can be made either 
by hand or by machine. The 
general method of obtaining the 
blank or pattern for the curved 




c 

306. 



PLAN 

Fig 

moulding is to average a line through the extreme points of the 
profile A, as I J, extending it until it intersects a line drawn at right 
angles to D B from the center B, as B H, at K. 

We will not go into any further demonstration about this curved 
work, as the matter will be taken up at its proper time later on. 

To obtain the pattern for the upper and lower return mouldings, 
proceed in precisely the same manner as explained in connection with 
returns B and D in Fig. 303. 

In Fig. 306 are shown the plan and elevation of a gable moulding 
in octagon plan. This problem should be carefully followed, as it 
presents an interesting study in projections; and the principles used in 
solving this are also applicable to other problems, no matter what 
angle or pitch the gable has. By referring to the plan, it will be seen 



SHEET METAL WORK 



225 



that the moulding has an octagon angle in plan a b c, while similar 
points in elevation a' b' c' run on a rake in one line, the top and foot 
of the moulding butting against the brick piers B and A. 

The method of proceeding with work of this kind is explained in 
detail in Fig 307, where the principles are thoroughly explained. Let 
A B C D E represent a plan view of the wall, over which a gable 
moulding is to be placed, as shown by G H IJ, the given profile of the 




SOFFIT PUN 



Fig. 307. 

moulding being shown by L M. Divide the profile into equal spaces 
as shown by the figures 1 to 8. Parallel to I H or J G, and through the 
figures mentioned, draw lines indefinitely as shown. Bisect the angle 
B C D in plan, and obtain the miter-line as follows : With C as center, 
and any radius, describe the arc N O. With N and O as centers, and 
any radius greater than C N or C O, describe arcs intersecting each 
other at P. From the point C, and through the intersection P, draw 
the miter-line C Q. Transfer the profile L M in elevation to the posi- 



226 



SHEET METAL WORK 



tion shown by R S in plan, dividing it into the same number of spaces 
as L M. Through the figures in the profile R S, and parallel to D C, 
draw lines intersecting the miter-line C Q, as shown. From the inter- 
sections on the miter-line, and parallel to C B, draw lines intersecting 
the surface B A. Now, at right angles to C D in plan, and from the 




M e SOFFIT PLAN 

Fig. 308. 

intersections on the miter-line C Q, draw vertical lines upward, inter- 
secting lines of similar numbers drawn from points in profile L M in 
elevation parallel to J G. A line traced through points thus obtained, 
as shown from 1' to 8', will be the miter-line in elevation. 

For the pattern for that part of the moulding shown by C D E Q' 
in plan, and H G 8' 1' in elevation, proceed as follows: At right 
angles to 1 H in elevation, draw the line T U, upon which place the 



SHEET METAL WORK 



227 



stretchout of the profile L M, as shown by the figures 1 to 8. At right 
angles to T U, and through these figures, draw lines, as shown, which 
intersect with lines of similar numbers drawn at right angles to 1 H 
from intersections on the miter-line 1' 8' and from intersections 
against the vertical surface H G. Lines traced through points thus 
obtained, as shown by V W X Y, will be the pattern for that part of 
the gable shown in plan by C D E Q' of Fig. 307. 

In Fig. 308, on the other hand, the position of the plan is changed, 
so as to bring the line A Q horizontal. At right angles to B C draw 
the vertical line C E, on which locate any point, as E. In the same 
manner, at right angles to C B, draw the vertical line B J indefinitely. 
From the point E, parallel to B C, draw the line E 8*, intersecting 
the line J B, as shown. Now take the distance from 8" to J in eleva- 
tion, Fig. 307, and set it off from 8" toward J in Fig. 308. Draw a line 
from J to E, which will represent the true rake for this portion of the 
moulding. Now take the various heights shown from 1 to 8 on the 
line Z Z in elevation in Fig. 307, and place them as shown by Z Z in 
elevation, Fig, 308, being careful to place the point 8 of the 
line Z Z on the line 8" E extended. At right angles to Z 
Z, and from points on same, draw lines, which intersect 
with lines drawn at right angles to B C from intersec- 
tions of similar numbers on C Q in plan. A line traced 
through points thus obtained, as shown by D E in eleva- 
tion, will be the miter-line on C Q in plan. 

From the intersections on the miter-line D E, and 
parallel to E J, draw lines, which intersect with lines 
drawn from intersections of similar numbers on A B in 
plan at right angles to B C. A line traced through points 
thus obtained, as shown by F J, will be the miter-line 
or line of joint against the pier shown in plan by B A. 

Before obtaining the pattern it will be necessary to obtain a true 
section or profile at right angles to the moulding F D. To do so, pro- 
ceed as follows : Transfer the given profile L M in elevation in Fig. 
307, with the divisions and figures on same, to a position at right angles 
to F D of Fig. 308, as shown at L. At right angles to F D, and from 
the intersections in the profile L, draw lines intersecting those of simi- 
lar numbers in F D E J. Trace a line through intersections thus ob- 




Fig. 309. 



228 



SHEET METAL WORK 



tained, as shown from 1 to 8, thus giving the profile M, or true sections 
at right angles to F D. 

For the pattern, proceed as follows: At right angles to F D, 
draw the line H K, upon which place the stretchout of the profile M, as 
shown by the figures. At right angles to H K, and through the figures, 
draw lines, which intersect with those of similar numbers drawn at 




Fig. 310. Fig. 311. 

right angles to F D from points of intersection in the miter-lines D E 
and J F, as shown. Lines traced through points thus obtained, as 
shown by N O P R, will be the pattern for the raking moulding shown 
in plan, Fig. 307, by A B C Q'. 

In Fig. 309 is shown a view of a spire, square in plan, intersecting 
four gables. In practice, each side A is developed separately in a 
manner shown in Fig. 310, in which first draw the center line through 
the center of the gable, as E F. Establish points B and C, from which 



SHEET METAL WORK 



229 



draw lines to the apex F. At pleasure, establish AD. At right angles 

to F E, and from B and J, draw the lines B H and J K respectively. 

For the pattern, take the distances B K, K A, and A F, and place them 

as shown by similar letters 

on the vertical line B F in 

Fig. 311. At right angles 

to B F, and through points 

B and A, draw lines as 

shown, making B H and B 

H 1 on the one hand, and 

A N and A O on the other 

hand, equal respectively to 

B H and A N in elevation in 

Fig. 310. Then, in Fig. 





Fig. 312. 



Fig. 313. 



311, draw lines from N to H to K to H l to O, as shown, which repre- 
sents the pattern for one side. 

In Fig. 312 is shown a perspective view of a drop B mitering 
against the face of the bracket C as indicated at A. The principles 
for developing this problem are explained in Fig. 313, and can be ap- 
plied to similar work no matter what the profiles of the drop or bracket 
may be. Let A B C D E represent the face or front view of the bracket 
drop, and F H G I the side of the drop and bracket. Divide one-half 
of the face, as D C, into equal spaces, as shown by the figures 1 to 7 
on either side, from which points draw horizontal lines crossing H G 
in side view and intersecting the face H I of the bracket at points 1' to 
7'. In line with H G, draw the line J K, upon which place the stretch- 
out of the profile B C D, as shown by 1 to 7 to 7 to 1 on J K. At right 
angles to J K, draw the usual measuring lines as shown, which inter- 
sect by lines drawn parallel to J K from similarly numbered intersec- 
tions on H I. Trace a line through the points thus obtained. Then 



230 



SHEET METAL WORK 




ELEVATION 



Fig. 314. 



will J K L be the pattern for the return of the drop on the face of the 
bracket. 

In Fig. 314, A shows a raking bracket placed in a gable moulding. 
When brackets are placed in a vertical position in any raking moulding, 
they are called "raking" brackets. B represents a raking bracket 
placed at the center of the gable. The patterns which will be develop- 
ed for the bracket A are also used for B, the cuts being similar, the only 

difference being that one-half the 
width of t h e bracket in B is 
formed right and the other half 
left, the two halves being then 
joined at the angle as shown. 

In Fig. 315 are shown the 
principles employed for obtain- 
ing the patterns for the side, 
face, sink strips, cap, and returns 
for a raking bracket. These 
principles can be applied to any 
form or angle in the bracket or 
gable moulding respectively. Let S U V T represent part of a 
front elevation of a raking cornice placed at its proper angles with 
any perpendicular line. In its proper position, draw the outline of the 
face of the bracket as shown by E G M O. Also, in its proper position 
as shown, draw the normal profile of the side of the bracket, indicated 
by 6-Y-Z-15; the normal profile of the cap-mould, as W and X; and 
the normal profile of the sink strip, as indicated by 10 10' 15' 15. 
Complete the front elevation of the bracket by drawing lines par- 
allel to E O from points 7 and 9 in the normal profile; and establish 
at pleasure the width of the sink strip in the face of the bracket, as at 
J K and L H. To complete the front elevation of the cap-mould of 
the bracket, proceed as follows : Extend the lines G E and M O of the 
front of the brackets, as shown by E 6 and O 6, on which, in a vertical 
position as shown, place duplicates (W 1 , W 2 ) of the normal profiles W 
and X, divided into equal spaces as shown by the figures 1 to 6 in W 1 
and W 2 . From these intersections in W 1 and W 2 , drop vertical lines, 
./hich intersect by lines drawn parallel to E O from similarly numbered 
intersections in X, and trace lines through the points thus obtained. 
Then will R E and O P represent respectively the true elevations, also 



SHEET METAL WORK 



231 



the true profiles, for the returns at top and foot of the cap of the raking 
bracket. 

Now divide the normal profile of the bracket into equal spaces, as 
shown by the figures 6 to 15, through which, parallel to E O, draw lines 
intersecting the normal sink profile from 10' to 15' and the face lines 
of the bracket EFG, JH, KL, and ONM, as shown. To obtain the 



FOR SIDE 
■ ~T 



N*^ 
PATTERN FOR^n- 
RETURN R E ^\ VJ> 




' WW 

ivWiV 

-^WVaTTERM 
-19713' FOR SINK 
S C~7ilM 4 ' STRIP 



true profile for the side of the bracket on the lines OM and GE, pro- 
ceed as follows : Parallel to OM, draw any line, as Y 1 Z 1 ; and at right 
angles to OM, and from the various intersections on the same, draw 
lines indefinitely, crossing to the line Y 1 Z 1 as shown. Now, measuring 
in each instance from the line YZ in the normal profile, take the various 
distances to points 6 to 15 and 15' to 10', and place them on similarly 
numbered fines measuring in each and every instance from the line 
Y 1 Z 1 , thus obtaining the points 6' to 15' and 15" to 10", as shown. 
Trace a line through the points thus obtained. Then will Y 1 6' 
7' 9' 10' 15' Z 1 be the pattern for the side of the raking bracket, 



232 



SHEET METAL WORK 



and 10' 10" 15" 15' the pattern for the sink strip shown by the 
lines K L and H J in the front. 

For the pattern for the face strip B, draw any line, as A 1 B 1 , at. 
right angles to G M, upon which place the stretchout of 10 15 in the 
normal profile, as shown from 10 to 15 on A 1 B 1 . Through these 
points, at right angles to A 1 B 1 , draw lines as shown, which intersect 
with lines drawn from similar intersections on the lines F G and H J. 
Trace a line through points thus obtained as shown by F° G° H° J°, 
which will be the pattern for the face B, B. 

For the pattern for the sink-face C, draw C 1 D 1 at right angles to 
(?rM, upon which place the stretchout of 10' 15' in the normal profile 
as shown from 10' to 15' on C 1 D 1 , through which, at right angles to 
C 1 D 1 , draw lines, which intersect by 
lines drawn from similar intersections 
on K L and H J. Trace a line through 
the points so obtained as J° K° L° H°, 
which is the pattern for the sink- 
face C. 

The pattern for the cap D and 
the face A will be developed in one 
piece, by drawing at right angles to 
EO the line E 1 F 1 . At right angles 





Fig. 316. Fig. 317. 

to E 1 F l , and through the figures, draw lines, which intersect with lines 
drawn at right angles to EO from similarly numbered intersections on 
REF and NOP. A line traced through the points thus obtained, as 
shown by R° E° F° and N° 0° P° will be the pattern for D and A. 

For the patterns for the cap returns R E and O P, draw any line 
at right angles to 1 1 in the normal profile, as H 1 G 1 , upon which 
place the stretchouts of the profiles R E and O P, being careful to carry 
each space separately onto the fine H 1 G 1 , as shown respectively by 
6 V l v and 6 X I s . Through these points draw lines at right angles to 
G 1 H 1 , which intersect by lines drawn at right angles to 1 1 from 



SHEET METAL WORK 



283 



similar numbers in W and X. Trace lines through the points thus 
obtained. Then will N 1 O 1 R 1 S 1 be the pattern for the lower return 
of the cap, R E; while J 1 M 1 L 1 K 1 will be the pattern for the upper re- 
turn, P O. 

In Fig. 316 is shown a perspective view of a gutter or eave- 
trough at an exterior angle, for which an outside miter would be re- 
quired. It is immaterial what shape the gutter has, the method of 
obtaining the pattern for the miter is the same. In Fig. 317 let 1 9 
10 represent the section of the eave-trough with a bead or wire 
! edge at ab c; divide the wire edge, including the gutter and flange, into 
an equal number of spaces, as shown by the small divisions d to 1 to 9 

to 10. Draw any vertical line, as . 

A B, upon which place the stretch- 
out of the gutter as shown by simi- 
lar letters and numbers on A B, 
through which, at right angles to 
A B , draw lines, which intersect by 



7\ 



ELEVATION 



re 




I 

» • » B 

___t_____fe; plan %"' __-__{__-• 
*-D -»_^____a__f* — C- 




Fig. 318. 



Fig. 319. 



Lines drawn parallel to AB from similar points in the section. Trace 
a line through the points thus obtained. Then will C D E F be the 
pattern for the outside angle shown in Fig. 316. 

If a pattern is required for an interior or inside angle, as is shown 
in Fig. 318, it is necessary only to extend the lines C D and F E in the 
pattern in Fig. 317, and draw any vertical line, as J H. Then will J D 
E H be the pattern for the inside angle shown in Fig. 318. 

In Fig. 319 are shown a plan and elevation of a moulding which 
has more projection on the front than on the side. In other words, A B 
represents the plan of a brick pier, around which a cornice is to be 
constructed. The projection of the given profile is equal to C, the 
profile in elevation being shown by C 1 . The projection of the front 
in plan is also equal to C, as shown by C 2 . The projection of the left 
side of the cornice should be only as much as is shown by D in plan. 
This requires a change of profile through D, as shown by D 1 . To ob» 



234 



SHEET METAL WORK 



tain this true profile and the various patterns, proceed as shown in 
Fig. 320, in which ABCD represents the plan view of the wall, against 
which, in its proper position, the profile E is placed and divided into 
equal spaces, as shown by the figures 1 to 12. Through 1 2, par- 
allel to C D, draw G F. Locate at pleasure the projection of the re- 



PATTERW TOR 
FRONT 

II 

\2 



1 ' St' 3' 4* 5' 6' 7WK)' 1 f 12* L 





1 !'■ i 
111. ' 



W H 

PATTERN 
- FOR 

RETURN 
C 



PLAN. 



IP ;n ji y,,,/,,,/,/,,/,/,/,/,P/////,/./////////,//,/,/t 



jj^^" i: -" : y--"-"/----- ^ 

G 12 f 



Fig. 



G 
320. 



turn mould, as B H, and draw H G parallel to B C, intersecting F G 
at G. Draw the miter-line in plan, G C. From the various divisions 
in the profile E, draw lines parallel to C D, intersecting the miter-line 
C G as shown. From these intersections, erect vertical lines indefi- 
nitely, as shown. Parallel to these lines erect the line K J, upon which 
place a duplicate of the profile E, with the various divisions on same, 
as shown by E 1 . Through these divisions draw horizontal lines in- 



SHEET METAL WORK 



235 



tersecting the similarly numbered vertical lines, as shown by the in- 
tersections 1 to 12'. Trace a line through these points. Then will 
F 1 be the true section or profile on H B in plan. 

For the pattern for the return H G C B in plan, extend the line 
B A, as B M, upon which place the stretchout of the profile F 1 , being 
careful to measure each space separately (as they are unequal), as 
shown by figures 1/ to 12' on M B. 

At right angles to this line and through the figures, draw lines, 
which intersect by lines drawn at right angles to H G from similar 
points on C G. Trace a 
line through the points 
thus obtained. Then 
will H 1 G 1 C 1 B 1 be the 
pattern for the return 
mould. 

The pattern for the 
face mould GCDF is 
obtained by taking a 
stretchout of the profile 
E and placing it on the 



TRUE PROFILE 
THROUGH 
1" 7" IN 
PLAN 





Fig. 321. 



Fig. 322. 



vertical line P O, as shown by similar figures, through which, at 
right angles to P O, draw lines intersecting similarly numbered lines 
previously extended from C G in plan. Trace a line through these 
intersections. Then will 1 B 1 C 1 12 be the miter pattern for the face 
mould. 

In Fig. 321 is shown a perspective view of a gore piece A joined 
to a chamfer. This presents a problem often arising in ornamental 



236 SHEET METAL WORK 

sheet-metal work, the development of which is given in Fig. 322. Let 
A B C D show the elevation of the corner on which a gore piece is re- 
quired. H 7 E in plan is a section through C D, and E F G H is 
a section through X I, all projected from the elevation as shown. The 
profile 1 7 can be drawn at pleasure, and at once becomes the pattern 
for the sides. Now divide the profile 1 7 into an equal number of 
spaces as shown, from which drop vertical lines onto the side 7' E 
in plan, as shown from 1' to 7 . From these points draw lines parallel 
to F G, intersecting the opposite side and crossing the line 7' 1" 
(which is drawn at right angles to F G 

rt - \ _ G from 7) at 1" 2" 3" 4" 5" 6". Draw any 

• / line parallel to C D, as K J, upon which 

J place all the intersections contained on 7' 

J 1" in plan, as shown by 1° to 7° on K J. 

/ From these points erect perpendicular lines, 

I which intersect by lines drawn from simi- 

larly numbered points in elevation parallel 
to C D. Through the points thus obtained 
trace a line. Then will l v to 7 V be the true 
profile on 7 1" in plan. 
For the pattern for the gore, draw any vertical line, as A B in Fig. 
323, upon which place the stretchout of the profile l v 7 V in Fig. 322, 
as shown by similar figures on A B in Fig. 323. At right angles to AB, 
and through the figures, draw lines as shown, Now, measuring in 
each instance from the line 7' I" in plan in Fig. 322, take 
the various distances to points 1' to 7', and place them 
in Fig. 323 on similarly numbered lines, measuring in 
each instance from the line A B, thus locating the points Fig. 324. 
shown. Trace a line through the points thus obtained. Then will 
F G 7 be the pattern for the gore shown in plan in Fig. 322 
by F G 7. 

In Fig. 324 is shown a face view of a six-pointed star, which often 
arises in cornice work. No matter how many points the star has, the 
principles which are explained for its development are applicable to 
any size or shape. Triangulation is employed in this problem, as 
shown in Fig. 325. First draw the half-outline of the star, as shown by 
A B C D E F G. Above and parallel to the line AG, draw JH of 
similar length, as shown. Draw the section of the star on A G in plan, 




SHEET METAL WORK 



237 




as shown by J K H. Project K into plan as shown at I, and draw the 
miter-lines B I, C I, D I, E I, and F I. As K H is the true length on 
I G, it is necessary that we find the true length on I F. Using I F as 
radius and I as center, draw an arc intersecting I G at a. From a 
erect a line cutting J H in section at b. 
Draw a line from b to K, which is the 
true length on I F. 

For the pattern, proceed as 
shown in Fig. 326. Draw any line, 
as K H, equal in length to K H in Fig. 
325. Then, using K b as radius and 
K in Fig. 326 as center, describe the 
arc b b, which intersect at a and a by 
an arc G G struck from H as center 
and with F G in plan in Fig. 325 as 
radius. Draw lines in Fig. 326 from 
K to a to H to a to K, which will be the pattern for one of the points 
of the star of which 6 are required. 

When bending the points on the line HK, it is necessary to have a 
stay or profile so that we may know at what angle the bend should be 
made. To obtain this stay, erect from the corner B in Fig. 325 a line 
intersecting the base-line J H at c, from which point, at right angles to 
J K, draw c d. Using c as center, and c d as radius, strike an arc inter- 
secting J H at e. From e drop a vertical line meeting A G in plan at 
d'. Set off i B 1 equal to i B, and draw a line 
from B to d' to B 1 , which is the true profile 
after which the pattern in Fig. 326 is to be 
bent. If the stay in Fig. 325 has been cor- 
rectly developed, then d' B 1 or d' B must equal 
e a in Fig. 326 on both sides. 

In Fig. 327 is shown a finished elevation 
of a hipped roof, on the four corners of which 
a hip ridge A A butts against the upper base B 
and cuts off on a vertical line at the bottom, as C and C. To obtain 
the true profile of this hip ridge, together with the top and lower cuts 
and the patterns for the lower heads, proceed as shown in Fig. 328, 
where the front elevation has been omitted, this not being necessary, 
as only the part plan and diagonal elevation are required. First draw 



PATTERN FOR 
^CORNER 




Fig. 326. 



238 



SHEET METAL WORK 




the part plan as shown by A B C D E F A, placing the hip or diagonal 
line F C in a horizontal position; and make the distances between the 
lines F A and C B and between F E and C D equal, because the roof 
in this case has equal pitch all around. (The same principles, how- 
ever, would be used if the roofs had unequal pitches.) Above 

the plan, draw the line 
G H. From the points 
F and C in plan, erect 
the lines F G and C I, 
extending C I to C 1 so 
that I C 1 will be the re- 
quired height of the roof 
above G I at the point 
C in plan. Draw a line 
from G to C 1 , and from 
C 1 draw a horizontal and 
vertical line indefinitely, 
as shown. Then will I G C 1 be a true section on the line of the 
roof on F C in plan. 

The next step is to obtain a true section of the angle of the roof at 
right angles to the hip line G C 1 in elevation. This is done by drawing 
at right angles to F C in plan, any line, as a b, intersecting the lines 
F A and F E as shown. Extend a b until it cuts the base-line G I in 
elevation at c. From c, at right angles to G C 1 , draw a line, as c d, 
intersecting G C 1 at d. Take the distance c d, and place it in plan on 
the line F C, measuring from i to d'. Draw a line from a to d' to b, 
which is the true angle desired. On this angle, construct, the desired 
shape of the hip ridge as shown by J, each half of which divide into 
equal spaces, as shown by the figures 1 to 6 to 1. As the line G C 1 rep- 
resents the line of the roof, and as the point d ' in plan in the true angle 
also represents that line, then take a tracing of the profile J with the 
various points of intersection on same, together with the true angle 
a d' b, and place it in the elevation as shown by J 1 and a' d" &', being 
careful to place the point d" on the line G C 1 , making a? b' parallel to 
G C 1 . From the various points of intersection in the profile J, draw 
lines parallel to F C, intersecting B C and A F at points from 1 to 6. 
as shown. As both sides of the profile J are symmetrical, it is necessary 
only to draw lines through one-half. 



SHEET METAL WORK 



239 



In similar manner, in elevation, parallel to G C 1 , draw lines 
through the various intersections in J 1 , which intersect by lines drawn 
at right angles to F C in plan from similarly numbered points on A F 



PATTERN FOR 
HIP RIDGE 




Fig. 328. 
said BC. Trace a line through the points thus obtained. Then will 
K L be the miter-line at the bottom, and M N the miter-line at the top. 
For the pattern, draw any line, as O P, at right angles to G C 1 , 



240 SHEET METAL WORK 

upon which place the stretchout of J in plan or J 1 in elevation, as shown 
by the figures 1 to 6 to 1 on O P ; and through these numbered points, 
at right angles to O P, draw lines, which intersect by lines drawn at 
right angles to G C 1 from similar intersections in the lower miter-line 
K L and upper miter-line N M. Trace a line through the points thus 
obtained. Then will R S T U be the desired pattern. 

In practice it is necessary only to obtain one miter-cut — either the 
top or the bottom — and use the reverse for the opposite side. In other- 
words, U T is that part falling out of R S, the same as R S is that part 
which cuts away from U T. The upper miter-cut butts against B in 
Fig. 327; while the lower cut requires a flat head, as shown at C. To 
obtain this flat head, extend the line I G in Fig. 328, as I W, upon 
which place twice the amount of spaces contained on the line A F in 
plan, as 6, 3 — 5, 4, 1, 2, as shown by similar figures on either side of 
6 on the line V W. From these divisions erect vertical lines, which 
intersect by lines drawn parallel to V W from similarly numbered 

intersections in the miter-line 
K L G. A line traced through 
the points thus obtained, as 
shown by X Y Z, will be the 
pattern for the heads. 

Where a hip ridge is re- 
quired to miter with the apron 
of a deck moulding, as shown 
in Fig. 329, in which B repre- 
sents the apron of the deck cornice, A and A the hip ridges mitering 
at a and a, a slightly different process from that described in the 
preceding problem is used. In this case the part elevation of the 
mansard roof must first be drawn as shown in Fig. 330. Let ABC 
K represent the part elevation of the mansard, the section of the 
deck moulding and apron being shown by D B E. Draw E X par- 
allel to B C. EX then represents the line of the roof. In its proper 
position, at right angles to B C, draw a half-section of the hip mould, 
as shown by F G, which is an exact reproduction of B E of the deck 
mould. Through the corners of the hip mould at Y and G, draw 
lines parallel to B C, which intersect by lines drawn parallel to B A 
from V, W, and E in the deck cornice. Draw the miter-line H I, 
which completes the part elevation of the mansard. 




Fig. 329. 



SHEET METAL WORK 



241 



Before the patterns can be obtained, a developed surface of the 
mansard must be drawn. Therefore, from B (Fig. 330), drop a ver- 
tical line, as B J, intersecting the line C K at J. Now take the dis- 
tance of B C, and place it on a vertical line in Fig. 331, as shown by 
B C 1 . Through these two points draw the horizontal lines B A and 
C K as shown. Take the projection J to C in Fig. 330, and place it as 




PART ELEVATION 

OF 

MANSARD ROOF 



PART PLAN 



Then 



TRUE 
SECTION 
ON O-P* 

Rl' 

Fig. 330. 

shown from C 1 to C in Fig. 331, and draw a line from C to B. 
will A B C K be the developed surface of A B C K in Fig. 330. 

As both the profiles B V W E and F Y G are similar, take a tracing 
of either, and place it as shown by D and D 1 respectively in Fig. 331. 
Divide both into the same number of equal spaces, as shown. Bisect 
the angle A B C by establishing a and 6, and, using these as centers, 



242 



SHEET METAL WORK 



by describing arcs intersecting at c; then draw d B, which represents 
the miter-line. Through the points in D and D 1 , draw lines parallel 
to their respective moulds, as shown, intersecting the miter-line B d 
and the base-line C C 1 . 

For the pattern for the hip, draw any line, as E F, at right angles 
to B C, upon which place twice the stretchout of D, as shown by the 
divisions 6 to 1 to 6 on EF. Through these divisions draw lines at 



PATTERN! FOR 
X *HIP RIDGE 




iff m 



d' 



5 6 



«*; 



DEVELOPED 
SURFACE OF 
MAN5ARD ROOF 



C C 

Fig. 331. 

right angles to E F, intersecting similarly numbered lines drawn at 
right angles to B C from the divisions onB d and C C 1 . Trace a line 
through the points thus obtained. Then will G H J L be the pattern 
for the hip ridge. 

When bending this ridge in the machine, it is necessary to know 
at what angle the line 1 in the pattern will be bent. A true section 
must be obtained at right angles to the line of hip, for which proceed as 
shown in Fig. 330. Directly in line with the elevation, construct a 
part plan LMNO, through which, at an angle of 45 degrees (because 
the angle L O N is a right angle), draw the hip line O M. Establish at 
pleasure any point, as P 1 on O M, from which erect the vertical line 
into the elevation crossing the base-line C K at P and the ridge-line 
C B at R. Parallel to O M in plan, draw O 1 P 2 , equal to O P 1 , as 
shown. Extend P 1 P 2 as P 2 R 1 , which make equal to PR in elevation. 



SHEET METAL WORK 



243 



Draw a line from R 1 to O 1 . Then O 1 R 1 P 2 represents a true section on 
OP 1 in plan. Through any point, as a, at right angles to OM, draw 
be, cutting L O and ON at b and c respectively. Extend b c until it 
intersects O 1 P 2 at d. From d, at right angles to O 1 R 1 , draw the line 
d e. With d as center, and de as radius, draw the arc e e', intersecting 
O 1 P 2 at e', from which point, at right angles to OM in plan, draw a 
line intersecting OM at e". Draw a lire from b to e" to c, which repre- 
sents the true section of the hip after which the pattern shown in Fig. 
331 is formed. 

The pattern for the deck mould D B in Fig. 330 is obtained in the 
same way as the square miter shown in Fig. 277; while the pattern for 
the apron D 1 in Fig. 331 is the same as the one-half pattern of the hip 
ridge shown by n H 1 6. 

In Fig. 332 is shown a front elevation of an eye-brow dormer. In 
this view ABC represents the front view of the dormer, the arcs being 




SECTION! 
THROUGH 
H J 



Fig. 332. 

struck from the center points D, E, and F. A section taken on the 
line H J in elevation is shown at the right; L M shows the roof of the 
dormer, indicated in the section by N; while the louvers are shown in 
elevation by O P and in section by RT. 

In Fig. 333 is shown how to obtain the various patterns for the 
various parts of the dormer. ABC represents the half-elevation of the 
dormer, and EFG a side view, of which EG is the line of the dormer^ 
EF that of the roof, and GF the line of the pitched roof against which 
the dormer is required to miter. 

The front and side views being placed in their proper relative 
positions, the first step is to obtain a true section at right angles to EF. 
Proceed as follows: Divide the curve A to B into a number of equal 
spaces, as shown from 1 to 9. At right angles to A C, and from the 
figures on A B, draw lines intersecting E G in side view as shown. 



244 



SHEET METAL WORK 



From these intersections, and parallel to EF, draw lines intersecting 
the roof-line GF at I 5 , 2 5 , 3 5 , etc. Parallel to EF, and from the point 




ONE HALF TRUE 
PROFILE ON LINE 
E-H IN SIDE VIEW 



ONE HALF PATTERN 

FOR SHAPE OF 
OPENING IN ROOF 



Fig. 333. 



G, draw any line indefinitely, as G II. At right angles to EF, and 
from the point E, draw the line EH, intersecting lines previously drawn, 



SHEET METAL WORK 



245 



at l 1 , 2 1 , 3 1 , etc., as shown. Now take a duplicate of the line E K, with 
the various intersections thereon, and place it on the center line AC 
extended as K J. At right angles to K J, and from the figures I 2 , 2 2 , 3 2 , 
etc., draw lines, which intersect with those of similar numbers drawn 
at right angles to CB, and from similarly numbered points on the curve 
A B. Trace a line through the points of intersection thus obtained. 
Then KLMJ will be one-half the true profile on the line E H in side 
view, from which the stretchout will be obtained in the development 
of the pattern. 

For the pattern for the roof of the dormer, draw at right angles 
to EF in side view the line N O, upon which place the stretchout of 
one-half the true profile on the line EH as shown by the small figures 
l 4 , 2 4 , 3 4 , etc. Then, at right angles to N O, and through the figures, 
draw lines, which intersect with those of similar numbers drawn at 
right angles to EF from intersections on EG and GF. Trace a line 
through the points thus obtained. Then will PRST represent one- 
half the pattern for the roof. 

To obtain the pattern for the shape of the opening to be cut into 
the roof, transfer the line GF, with the various intersections thereon, 
to any vertical line, as UV, as shown 
by the figures l 6 , 2 6 , 3 6 , etc. In 
similar manner, transfer the line 
CB in front view, with the various 
intersections on same, to the line 
ZW, drawn at right angles to UV, 
as shown by the figures 1, 2, 3, etc. 
At right angles to UV, and from 
the figures, draw lines, which in- 
tersect with those of similar num- 
bers drawn at right angles to YZ. B 
Through these points, trace a line. Fi S- 334 - 
Then will UXYZ be the half-pattern for the shape of the opening 
to be cut into the main roof. 

For the pattern for the ventilating slats or louvers, should they 
be required in the dormer, proceed as shown in Fig. 334. In this 
figure, A B C is a reproduction of the inside opening shown in Fig. 333. 
Let 1, 2, 3, 4, 5 in Fig. 334 represent the sections of the louvers which 
will be placed in this opening. As the methods of obtaining the pat- 



HALF FATTERN FOR 
LOUVRE *4 

D J1_ F 




240 



SHEET METAL WORK 



A- 



terns for all louvers are alike, the pattern for louver No. 4 will illus- 
trate the principles employed. Number the various bends of louver 
No. 4 as shown by points 6, 7, 8, and 9. At right angles to A B, and 
from these points, draw lines intersecting the curve A C as 6 1 , 7 1 , 4 1 , 8\ 
and 9 1 . On B A extended as E D, place the stretchout of louver No. 4 
as shown by the figures on ED. Since the miter-line AC is a curve, 
it will be necessary to introduce intermediate points between 7 and 8 
of the profile, in order to obtain this curve in the pattern. In this 
instance the point marked 4 has been added. 

Now, at right angles to DE, and through the figures, draw lines, 
which intersect with those of similar numbers, drawn parallel to AB 

from intersections 6 1 to 9 1 
on the curve AC. A line 
traced through the points 
thus obtained, as FKJH, 
will be the half-pattern 
for louver No. 4. The 
pattern for the face of 
the dormer is pricked 
onto the metal direct 
from the front view in 
^^^h,,,,,,,,,,,,,,,,^,,^,,,/,,//^. Fig. 333, in which A 8 
B C is the half-pattern. 
In laying out the 
patterns for bay window 
work, it often happens 
that each side of the window has an unequal projection, as is shown 
in Fi<*. 335, in which DEF shows an elevation of an octagonal base of 
a bay window having unequal projections. All that part of the bay 
above the line AB is obtained by the method shown in Fig. 290, while 
the finish of the bay shown by ABC in Fig. 335 will be treated here. 
In some cases the lower ball C is a half-spun ball. A 1 B 1 F 1 is a true 
section through A B. It will be noticed that the lines Ca, Cc, and Cd, 
drawn respectively at right angles to ab, be, and cd, are each of different 
lengths, thereby making it necessary to obtain a true profile on each 
of these lines, before the patterns can be obtained. This is clearly 
explained in connection with Fig. 336, in which only a half-elevation 
and plan are required as both sides are symmetrical. First draw the 





SHEET METAL WORK 



247 



center line AB, on which draw the half-elevation of the base of the 
bay, as shown by CDE. At right angles to AB draw the wall line 
in plan, as FK; and in its proper position in relation to the line CD in 
elevation, draw the desired half-plan, as shown by GHIJ. From the 
corners H and I draw the miter-lines HF and IF, as shown. As DE 




HALF PATTERN 
FOR 3 



Fig. 336. 

represents the given profile through FG in plan, then divide the profile 
DE into an equal number of spaces as shown by the figures 1 to 13. 
From these points drop vertical lines intersecting the miter-line FH 
in plan, as shown. From these intersections, parallel to HI, draw 
lines intersecting the miter-lines IF, from which points, parallel to I J, 
draw lines intersecting the center line FB. Through the various 
points of intersection in DE, draw horizontal lines indefinitely right 
and left as shown. 



248 SHEET METAL WORK 

If for any reason it is desired to show the elevation of the miter- 
line FI in plan (it not being necessary in the development of the pat- 
tern), then erect vertical lines from the various intersections on FI, 
intersecting similar lines in elevation. To avoid a confusion in the 
drawing, these lines have not been shown. Trace a line through 
points thus obtained, as shown by D 1 13, which is the desired miter- 
line in elevation. 

The next step is to obtain the true profile at right angles to HI 
and I J in plan. To obtain the true profile through No. 3 in plan, take 
a tracing of J F, with the various intersections thereon, and place it on 
a line drawn parallel to CD in elevation, as J 1 F 1 , with the intersections 
1 to 13, as shown. From these intersections, at right angles to J 1 F 1 , 
erect lines intersecting similar lines drawn through the profile DE in 
elevation. Trace a line through the points thus obtained, as shown 
by V to 13', which represents the true profile for part 3 in plan. At 
right angles to IH in plan, draw any line, as ML, and extend the va- 
rious lines drawn parallel to IH until they intersect LM at points 1 to 
13, as shown. 

Take a tracing of LM, with the various points of intersection, 
and place it on any horizontal line, as L 1 M 1 , as shown by the figures 
1 to 13, from which, at right angles to L 1 M 1 , erect vertical lines inter- 
secting similarly numbered horizontal lines drawn through the profile 
DE. Trace a line through the points thus obtained. Then will 
1" — 13" be the true profile through No. 2 in plan at right angles to HI. 

For the pattern for No. 1 in plan, extend the line FK, as NO, upon 
which place the stretchout of the profile DE as shown by the figures 
1 to 13 on NO. At right angles to NO, and from the figures, draw 
lines, which intersect with lines (partly shown) drawn parallel to FG 
from similar intersections on the miter-line FH. Trace a line through 
the points thus obtained ; then will IP 13 be the pattern for part 1 
in plan. 

At right angles to H I, draw any line, as T U, upon which place 
the stretchout of profile No. 2, being careful to measure each space 
separately, as they are all unequal, as shown by the small figures 1" to 
13" on TU. Through these figures, at right angles to TU, draw lines 
as shown, which intersect by lines (not shown in the drawing) drawn 
at right angles to I H from similar points on the miter-lines HF and FI. 



SHEET METAL WORK 249 

Trace a line through the points thus obtained. Then will V W X be 
the pattern for part 2 in plan. 

For the half-pattern for part 3 in plan, extend the center line A B 
in plan as B R, upon which place the stretchout of the true profile for 
3, being careful to measure each space separately, as shown by the 
figures 1' to 13' on BR. At right angles to B R draw lines through 
the figures, which intersect by lines drawn at right angles to J I from 
similar points of intersection on the miter-line F I. A line traced 
through points thus obtained, as 1' S 13', will be the half-pattern 
for part 3. 

DEVELOPMENT OF BLANKS FOR CURVED MOULDINGS 

Our first attention will be given to the methods of construction, 
it being necessary that we know the methods of construction before 
the blank can be laid out. For example, in Fig. 337 is a part elevation 
of a dormer window, with a semicircular top whose profile has an ogee, 
fillet, and cove. If this job were undertaken by a firm who had no 
circular moulding machine, as is the case in many of the smaller shops, 
the mould would have to be made by hand. The method of construc- 
tion in this case would then be as shown in Fig. 338, 
which shows an enlarged section through a b in Fig. 
337. Thus the strips a, b, and c in Fig. 338 would be 
cut to the required size, and would be nothing more 
than straight strips of metal, while d d! would be an 
angle, the lower side d' being notched with the shears 
and turned to the required circle. The face strips e, 
f, and h would represent arcs of circles to correspond 
to their various diameters obtained from the full-sized 
elevation. These face and sink strips would all be 
soldered together, and form a succession of square angles, as shown, in 
which the ogee, as shown by i j, and the cove, as shown by m, would be 
fitted. In obtaining the patterns for the blanks hammered by hand, 
the averaged lines would be drawn as shown by Jc I for the ogee and 
n o for the cove. The method or principles of averaging these and 
other moulds will be explained as we proceed. 

In Fig. 339 is shown the same mould as in the previous figure, 
a different method of construction being employed from the one made 
by hand »nd the one hammered up by machine. In machine work this 




250 



SHEET METAL WORK 



mould can be hammered in one piece, 8 feet long or of the length of the 
sheets in use, if such length is required, the machine taking in the full 





Fig. 338. Fig. 339. 

mould from A to B. The pattern for work of this kind is averaged 
by drawing a line as shown by CD. This method will also be ex- 
plained more fully as we proceed. 

SHOP TOOLS EMPLOYED 
When working any circular mould by hand, all that is required 
in the way of tools is various-sized raising and stretching hammers, 
square stake, blow-horn stake, and mandrel including raising blocks 
made of wood or lead. A first-rate knowledge must be employed 
by the mechanic in the handling and working of these small tools. In 
a thoroughly up-to-date shop will be found what are known as "curved 
moulding" machines, which can be operated by foot or power, and 
which have the advantage over hand operation of saving time and 
labor, and also turning out first-class work, as all seams are avoided. 

PRINCIPLES EMPLOYED FOR OBTAINING APPROXIMATE 
BLANKS FOR CURVED MOULDINGS HAMMERED BY HAND 

The governing principles underlying all such operations are the 
same as every sheet-metal worker uses in the laying out of the simple 
patterns in flaring ware. In other words, one who understands how to 
lay out the pattern for a frustum of a cone understands the principles 
of developing the blanks for curved mouldings. The principles will 
be described in detail in what follows, 

Our first problem is that of obtaining a blank for a plain flare, 
shown in Fig. 340. First draw the center line A B, and construct the 
half-elevation of the mould, as C P E F. Extend D E until it inter- 



SHEET METAL WORK 



251 



sects the center line A B at G. At right angles to A B from any point, 
as H, draw H 1 equal to C D, as shown. Using H as center, and with 
H 1 as radius, describe the quarter-circle 1 7, which is a section on 
C D. Divide 1 7 into equal spaces, as shown. Now using G as center, 
with radii equal to G E and G D, describe the arcs D 7' and E E°. 
From any point, as V, draw the radial line V G, intersecting the inner 
arc at E x . Take a stretchout of the quarter-section; place it as shown 





Fig. 340. 



Fig. 341. 



from 1' to T ; and draw a line from7' to G, intersecting the inner arc 
at E°. Then will E K V T E° be the quarter-pattern for the flare D E 
in elevation. If the pattern is required in two halves, join two pieces; 
if required in one piece, join four pieces. 

In Fig. 341 is shown a curved mould whose profile contains a cove. 
To work this profile, the blank must be stretched with the stretching 
hammer. We mention this here so that the student will pay attention 
to the rule for obtaining 'patterns for stretched moulds. First draw the 
center line A B ; also the half-elevation of the moulding, as C D E F. 
Divide the cove E D into an equal number of spaces, as shown from 



252 



SHEET METAL WORK 




HALF 
ELEVATION <*J , 
aQjC > 



a to e. Through the center of the cove c draw a line parallel to e a, 
extending it until it meets the center line A B at G, which is the center 
point from which to strike the pattern. Take the stretchout of the 
cove c e and c a, and place it as shown by c e' and c a'. When stretch- 
ing the flare a' e' , c remains stationary, e' and a' being hammered to- 
wards e and a respectively. Therefore, from c erect a vertical line 
intersecting H 1, drawn at right angles to A B, at 1. Using H as center 
and H 1 as radius, describe the arc 1 7, which divide into equal 

spaces as shown. With G as center, 
and radii equal to G a', Gc, and G e', 
describe the arcs e" e", V 7', and a" 
a". Draw a line from e" to G, inter- 
secting the center and lower arcs at 
1' and a". Starting from V, lay off 
the stretchout of the quarter-section as 
shown from V to 7'. Through 7' draw 
a line towards G, intersecting the in- 
ner arc at a"; and, extending the line 
upward, intersect the outer arc at e" . 
Then will a" e" e" a" be the quarter- 
pattern for the cove E D in elevation. 
If the quarter-round N O were re- 
quired in place of the cove E D, then, 
as this quarter-round would require to 
be raised, the rule given in the former 
Instruction Paper on Sheet Metal 
Work would be applied to all cases of raised mouldings. 

In Fig. 342 is shown a curved mould whose profile is an ogee. In 
this case as in the preceding, draw the center line and half-elevation, 
and divide the ogee into a number of equal parts, as shown from a to h. 
Through the flaring portion of the ogee, as c e, draw a line, extending 
it upward and downward until it intersects the center line A B at G. 
Take the stretchouts from a to c and from e to h and place them re- 
spectively from c to a' and from e to h' on the line In! G. Then, in work- 
ing the ogee, that portion of the flare from c to e remains stationary; 
the part from e to h' will be stretched to form e h ; while that part shown 
from c to a' will be raised to form c a. From any point in the station- 
ary flare, as d, erect a line meeting the line H 1, drawn at right 




PATTERN 



Fig. 342. 



SHEET METAL WORK 



253 



angles to A B, at 1. Using H as center and H 1 as radius, describe 
the quarter-section, and divide same into equal spaces, as shown. 
With G as center and with radii equal to G a', G d, and G h', describe 
the arcs a" a", V 7', and h" h". From h" draw a line to G. 
Starting at 1', lay off the stretchout of the section as shown from 1' to 
7'. Through T draw a 
line to G, as before de- 
scribed. Then will h" a" 
a" h" be the quarter-pat- 
tern for the ogee E D. 

In Fig. 343 is shown 
how the blanks are de- 
veloped when a bead 
moulding is employed. 
As before, first draw the 
center line A 1 B 1 and the 
half-elevation A B C D. 
As the bead takes up f 
of a circle, as shown by 
ace], and as the pat- 
tern for / e will be the 
same as for e c, then will 
the pattern for c e only 
be shown, which can also 
be used for e /. Bisect 
a c and c e, obtaining 
the points b and d, 
which represent the 
stationary points in the 
patterns. Take the 
stretchouts of b to a and 
b to c, and place them g ' ' 

as shown from 6 to a' and from b to c' ; also take the stretchouts 
of d to c and d to e, and place them from d to c' and from d to e' on 
lines drawn parallel respectively to a c and c e from points b and 
d. Extend the lines e' cf and c' a! until they intersect the center 
line A 1 B 1 at E and F respectively. From the points b and d 
erect lines intersecting the line G 1, drawn at right angles to A 1 




1 /,' 


PATTERN 




4' 


1 ,* 








i 






5' 




254 



SHEET METAL WORK 




B 1 , at 14 and 1 respectively. Using G as center, and with radii 
equal to G 14 and G 1, describe quarter-sections, as shown. Divide 
both into equal parts, as shown from 1 to 7, and from 8 to 14. With 
E as center, and with radii equal to E c', E d, and E e, describe the 
arcs c" c", d' d', and e" e". From any point on one end, as e", 
draw a radial line to E, intersecting the inner arcs at d' and c". Now 
take the stretchout of the section from 1 to 7, and, starting at d', lay 
off the stretchout as shown from 1' to 7'. Through 7 draw a line 
towards E, intersecting the inner arc at c" and the outer one at c". 
Then will c" e" e" c" be the quarter-pattern for that part of the 

bead shown by c e, also for 

e /, in elevation. For the 

pattern for that part shown 

by ac, use F 1 as center; and 

with radii equal to F a, F b, 
Fig. 344. and F c, describe the arcs 
a" a", b' b', and c" c". From any point 
on the arc b' b', as 8', lay off the stretch- 
out of the quarter-section 8 14, as 
shown from 8' to 14'. Through these 
two points draw lines towards F 1 , in- 
tersecting the inner arcs at a" a"; and 
extend them until they intersect the 
outer arc at c" and c". Then will 
c" a" a" c" be the desired pattern. 

In Fig. 344 is shown an illustra- 
tion of a round finial which contains 
moulds, the principles of which have already been described in 
the preceding problems. The ball A is made of either horizontal 
or vertical sections. In Fig. 345 is shown how the moulds in a finial 
of this kind are averaged. The method of obtaining the true length 
of each pattern piece will be omitted, as this was thoroughly covered 
in the preceding problems. First draw the center line A B, on either 
side of which draw the section of the finial, as shown by C D E. The 
blanks for the ball a will be obtained as explained by the devel- 
opment shown on page 106 of this volume. The mould b is 
averaged as shown by the line e /, extending same until it intersects 
the center line at h, e f representing the stretchout of the mould 




SHEET METAL WORK 255 

obtained, as already explained elsewhere in the text. Using h as 
center, with h f and h e as radii, describe the blank b°. 

In the next mould, c c', a seam is located in same as shown by 
the dotted line. Then average C by the line i j, extending same until 
it meets the center line at k; also average c' by the line I m, extending 
this also until the center line is intersected at n. Then i j and I m 
represent respectively the stretchouts of the mould c c', the blanks c° 
and c x being struck respectively from the centers Jc and n. The mould 
b' b" also has a seam, as shown by the dotted line, the moulds being 
averaged by the lines p o and s t, which, if extended, intersect the 
center line at r and u. These points are the centers, respectively, for 
striking the blanks b° and 6 X . The flaring piece d is struck from the 



"^^ 




Fig. 346. 

center x, with radii equal to x w and x v, thus obtaining the blank d°. 

By referring to the various rules given in previous problems, the 
true length of the blanks can be obtained. 

The principles used for blanks hammered by hand can be applied 
to almost any form that will arise, as, for example, in the case shown 
in Fig. 346, in which A and B represent circular leader heads; or in 
that shown in Fig. 347, in which A and B show two styles of balusters, 
a and b (in both) representing the square tops and bases. Another 
example is that of a round finial, as in Fig. 348, A showing the hood 
which slips over the apex of the roof. While these forms can be 
bought, yet in some cases where a special design is brought out by the 
architect, it is necessary that they be made by hand, especially when 
but one is required. 

The last problem on handwork is shown in Fig. 349 — that of 
obtaining the blanks for the bottom of a circular bay. The curved 
moulding A will be hammered by hand or by machine, as will be ex- 



256 



SHEET METAL WORK 



plained later on, while the bottom B is the problem before us. The 
plan, it will be seen, is the arc of a circle; and, to obtain the various 
blanks, proceed as shown in Fig. 350, in which A B C is the elevation 
of the bottom of the bay, I J K being a plan view on A C, showing the 




<__3 




Fig. 347. 
curve struck from the center H. In this case the 
front view of the bottom of the bay is given, and 
must have the shape indicated by A B C taken on the 
line I J in plan. It therefore becomes necessary to 
establish a true section on the center line SK in 
plan, from which to obtain the radii for the blanks or 





1 — 








=S I 






s? 71 + 




ELEVATION 


J i \ 

!.I 

i 

1 
i 




\^ PLAN ^ 






c_> 



Fig. 349. Fig. 34S. 

patterns. To obtain this true section, divide the curve A B into any 
number of equal parts, as shown from 1 to 6. From the points of 
division, at right angles to A C, drop lines as shown, intersecting the 
wall line I J at points 1' to 6'. Then, using H as center, and radii 
equal to H 6', H 5', H 4', H 3', and H 2', draw arcs crossing the 
center line D E shown from 1" to 6". At any convenient point 



SHEET METAL WORK 



257 



opposite the front elevation draw any vertical line, as T U. Extend 
the lines from the spaces in the profile A B until they intersect 
the vertical line T U as shown. Now, measuring in every instance 
from the point S in plan, take the various distances to the num- 




\ 



E 
Fig. 350. 

bered points in plan and place them upon lines of 

similar numbers, measuring in every instance from 

the line T U in section. Thus take the distance 

S K in plan, and place it as shown from the line 

T U to K 1 ; then again, take the distance from S to 2" 

in plan, and place it as shown from the line T U to 2" on 

line 2 in section. Proceed in this manner until all the points \ \ 

in the true section have been obtained. Trace a line as mn 

shown, when \" to 6" to Y will be the true section on the 

line S K in plan. \ 

It should be understood that the usual method for 
making the bottom of bays round in plan is to divide the profile of 
the moulding into such parts as can be best raised or stretched. As- 
suming that this has been done, take the distance from \" in plan to 
the center point H, and place it as shown from 1" to L in section. 
From the point L, draw a vertical line L M, as shown. For the pat- 
tern for the mould 1" 2" , average a line through the extreme points, 
as shown, and extend the same until it meets L M at N. Then, 
with N as center, and with radii equal to N 2" and N I", describe 



M 



258 



SHEET METAL WORK 



the blank shown. The length of this blank is obtained by measur- 
ing on the arc 1' V in plan, and placing this stretchout on the arc 1" 
of the blank. The other blanks are obtained in precisely the same 
manner. Thus P is the center for the blank 2" 3"; R, for the blank 
3" 4"; O, for the blank 4" 5"; and M, for the blank 5" 6". 

The moulds 1" 2", 2" 3", and 3" 4" will be raised; while 
the blanks 4" 5" and 5" 6" will be stretched. 

APPROXIMATE BLANKS FOR CURVED MOULDINGS 
HAMMERED BY MACHINE 

The principles employed in averaging the profile for a moulding 
to be rolled or hammered by machine do not differ to any material 
extent from those used in the case of mouldings hammered by hand. 
Fig. 351 shows the general method of aver- 
aging the profile of a moulding in determin- 
ing the radius of the blank or pattern. It 
will be seen that A B is drawn in such a 
manner, so to speak, as to average the in- 
equalities of the profile D C required to be 
made. Thus distances a and b are equal, as 
are the distances c and d, and e and /. It is 
very difficult to indicate definite rules to be 
observed in drawing a line of this kind, or, 
in other words, in averaging the profile. 
Nothing short of actual experience and intimate knowledge of the 
material in which the moulding is to be made, will enable the operator 



SECTION 



Fig. 352. 

to decide correctly in all cases. There is, however, no danger of 
making very grave errors in this respect, because the capacity of 
the machines in use is such, that, were the pattern less advanta- 
geously planned in this particular than it should be, still, by passing 
it through the dies or rolls an extra time or two, it would be brought 
to the required shape. 




Fig. 351. 




SHEET METAL WORK 



259 



In Fig. 352 is shown a part elevation of a circular moulding as it 
would occur in a segmental pediment, window cap, or other structure 
arising in sheet-metal cornice work. B shows the curved moulding, 
joining two horizontal pieces A and C, the true section of all the moulds 
being shown by D. 

In this connection it may be proper to remark that in practice, 
no miters are cut on the circular blanks, the miter-cuts being placed on 
the horizontal pieces, and the circular moulding trimmed after it has 
been formed up. 

In Fig. 353 is shown the method of obtaining the blanks for 
mouldings curved in elevation, no matter what their radius or profile 




U— 



B E 



Fig. 353. 

may be. First draw the center line A B, and, with the desired center, 
as B, describe the outer curve A. At right angles to A B, in its proper 
position, draw a section of the profile as shown by C D. From the 
various members in this section, project lines to the center line A B, 
as 1, 2, 3, and 4; and, using B as center, describe the various arcs and 
complete the elevation as shown by A B C in Fig. 352, only partly 
shown in Fig. 353. In the manner before described, average the 
profile C D by the line c d, extending it until it intersects the line drawn 
through the center B at right angles to A B, at E. Then E is the center 
from which to strike the pattern. Centrally on the section C D, estab- 
lish e on the line c d, where it intersects the mould, and take the 
stretchout from e to C and from e to D, and place it as shown respec- 
tively from e to c and from e to d on the line c d. Now, using E as 



2bO 



SHEET METAL WORK 



V 



ELEVATION 




Fig. 354. 



center, with radii equal to E d, E e, and E c, describe the arcs d f d" , 
e' e", and c' c* '. Draw a line from c' to E, intersecting the middle and 
inner arc at e' and d'. The arc c' e" then becomes the measuring line 

| to obtain the length of the pattern, the length 

being measured on the arc 2 in elevation, 
which corresponds to the point e in section. 

In Fig. 354 is shown the elevation of a 
moulding A curved in plan B, the arc being- 
struck from the given point a. This is apt to 
occur when the moulding or cornice is placed 
on a building whose corner is round. To ob- 
tain the pattern when the moulding is curved 
in plan, proceed as shown in Fig. 355. Draw 
the section of the moulding, as A B, A C be- 
ing the mould for which the pattern is desired. 
C B represents a straight strip which is at- 
tached to the mould after it is hammered or rolled to shape. In 
practice the elevation is not required. At pleasure, below the sec- 
tion, draw the horizontal line E D. From the extreme or outside 
edge of the mould, as b, 
drop a line intersecting the 
horizontal line ED at E. 
Knowing the radius of the 
arc on b in section, place it 
on the line E D, thus ob- 
taining the point D. With 
D as center, describe the 
arc E F, intersecting a line 
drawn at right angle to E 
D from D. Average a line 
through the section, as G 
H, intersecting the line D F, 
drawn vertical from the cen- 
ter D, at J. Establish at 
pleasure the stationary 




Fig. 355. 



point a, from which drop a line cutting E D at a'. Using D as 
center, and with D a' as radius, describe the arc a' a", which is the 
measuring line when laying out the pattern. Now take the stretch- 



SHEET METAL WORK 



201 



outs from a to & and from a to c, and place them on the averaged 
line from a to G and from a to H respectively. Using J as center, 
with radii extending to the various points G, a, and H, describe the 
arcs G G 1 , a a"', and H H 1 . On 
the arc a' a'", the pattern is 
measured to correspond to the 
arc a' a" in plan. 

In Fig. 356 is shown a front 
view of an ornamental bull's-eye 
window, showing the circular 
mould A B C D, which in this 
case we desire to lay out in one 
piece, so that, when hammered 
or rolled in the machine, it will 
have the desired diameter. The 
same principles can be applied 
to the upper mould E F, as were 
used in connection with Figs. 
352 and 353. Fig< 356 ' 

To obtain the blank for the bull's-eye window shown in Fig. 350 
proceed as shown in Fig. 357. Let A B C D represent the elevatioi? 
of the bull's-eye struck from the center E. Through E draw the hori 





ELEVATION 

Fig. 357. 



zontal and perpendicular lines shown. In its proper position, draw a 
section of the window as shown by F G. Through the face of the 
mould, as H I, average the line H 1 1 1 , extending it until it intersects 



262 



SHEET METAL WORK 



the center line B D at J. Where the average line intersects the mould 
at a, establish this as a stationary point; and take the stretchouts from 
a to I and from a to H, and lay them off on the line H 1 1 1 from a to I 1 

and a to H 1 respectively. As 1 
5 in elevation represents the 
quarter-circle on the point a 
in section, divide this quarter- 
circle into equal spaces, as 
shown. Now, with radii equal 
to J I 1 , J a, and J H 1 , and with 
J in Fig. 358 as center, de- 
scribe the arcs H H, a a, and 
I I. From any point, as H, 
on one side, draw a line to J, 
intersecting the middle and in- 
Take the stretchout of the quarter-circle from 
1 to 5 in elevation in Fig. 357, and place it on the arc a a as shown 
from 1 to 5. Step this off four times, as shown by 5', 5", and 5"' '. 
From J draw a line through 5'", intersecting the inner and outer arcs 
at I and H. Then will H a a H be the full pattern. 




Fig. 358 
ner arcs at a and I. 



PRACTICAL PROBLEMS IN MENSURATION 
FOR SHEET METAL WORKERS. 



A square tank, Fig. 1, is required whose capacity should be 
200 gallons, the sides b a and a c each to be 30 inches ; how high 
must c d be, so that the tank will hold the desired quantity ? 

Suppose the height c d is to be 5L| inches, and the tank is to 



d£ 



CAPACITY 
200 GALLONS 





Fig. 1. 

have similar capacity, and one side c a is to be 20 inches wide, 
how long must the alternate side a b be, so that the tank will 
hold 200 gallons ? 

A round tank, Fig. 2, is to be constructed whose capacity 
should equal 510 gallons, and be 5 feet high from c to a; what 
must its diameter a b be, so as to hold the desired capacity ? 

Suppose the diameter of 
the tank is to be 50 inches 
as a b ; what must its height 
a c be, so that the tank will 
hold 510 gallons ? 

A large drip pan, Fig. 3, is 
to be constructed whose ca- 




Fig. 3. 



pacity should be 165 gallons, and whose top measurements a b and b e 
are 60 X 40 inches respectively, and bottom measurements d e and 



PROBLEMS IN MENSURATION 



ef2>4i X 54 inches respectively; what must its height m n be, so 
as to hold the desired volume, ? 

A round tapering measure, Fig. 4, is to be constructed whose 
volume will equal 42 quarts; its bottom diameter a b is to be 14 





Fig. 4. 

inches, its top diameter c d 18 inches; what must its height ef be 
to hold the desired quantity ? 

An elliptical tapering tank, Fig. 5, is to be constructed whose 
major axis m b is 24 inches, and minor axis c d 14 inches at the 
top, while at the bottom the major axis ef'is 20 inches, and minor 
axis g h 10 inches; the capacity of the tank should equal 44 
quarts; what must the height m n be, so that the tank will hold 
the desired amount ? 

A tank, Fig. 6, is to be constructed with semicircular ends 
-Mb _£ 



fc= 



CAPACITY 30 GALLONS 



r 



U. 




O-r— — 1\) 

Pig. 6. Fig. 7. 

whose capacity should equal 30 gallons; the length a b to be 20 
inches, and the diameters of c and d to be each 10 inches; what 
must the height <?,/be, so that the tank will hold the desired 
quantity ? 

Suppose the height efis to be 24 inches, the diameters c and 
d each 11 inches; what must the length of a b be, so that the tank 
will hold 30 gallons ? 



PROBLEMS IN MENSURATION 



In Fig. 7 is shown a fitting used in ventilation piping; the 
diameter a b is 11^ inches and it is desired that the oblong pipe 
on the opposite end shall have an area similar to the round pipe a b; 
if <?ymust be 5 inches, what must c d be so that both areas are alike ? 

Suppose the pipe is to be square in place of oblong, what must 
the length of each side be, so that both ends have similar area ? 

In Fig. 8, a b is 40 inches in diameter; and each one of the 
branches c, d, and e are to have equal diameters, what must the 
diameter of the branches be, so that the combined area of c, d f 
and e will equal the area of a b ? 

If c is 10 inches in diameter, 
what must be the diameter of a b 
the branches ? 

Fig. 9 shows a transition piece from a round pipe a to an 



d 12 inches, and e 8 inches, 
to have the combined area of 




ah- 



Fiar. 8. 




c, ,d 


b 


u 



Figo 10. 



elliptical pipe b, both sections to have similar area; if the round 
pipe is 24 inches in diameter, and the major axis of the elliptical 
pipe must be 32 inches, what must the minor axis of b be so that 
the area at b will equal the area of a ? 

If the minor axis of b is to be 16 inches and the major axis 35 
inches, what must the diameter of a be, so that both sections will 
have similar area ? 

In Fig. 10, a is 20 inches in diameter and forms a transition 
to an oblong pipe with semicircular end; the semicircular ends 
are to be 10 inches in diameter; what must the length of c d be, 
so that the area of b will be equal to the area of a ? 

If the pipe b measured 40 X 11 inches, having semicircular 
ends, what must the diameter of a be, so that both sections are 
equal in area ? 

If a is 20 inches in diameter and the upper section was to be 



PROBLEMS IN MENSURATION 



rectangular in shape, 8 inches wide, what would the length of the 
upper section be ? 

Suppose the upper section h was desired to be square, what 
must the length of each side be, to have an area similar to a ? 

In Fig. 11 is shown the illustration of an ordinary steel square, 
and the method is given of obtaining accurate diameters of pipes, 
round or square, without any computation whatever, the rule being 
based on the geometrical principle that the square of the hypothe- 
nuse of a right angle triangle is equal to the sum of the squares 
of its base and altitude. To illustrate the rule, Fig. 12 has been 




12 3 4 5 



7 6 9 10 II 12 13 14 15 16 17 16 19 20 21 22 23 24 

Fig. 11. 



prepared. Let A represent a round or square pipe, 20 inches across, 
and B a round or square pipe 12 inches across; it is desired to 
take a branch from the main so that the two branches B and C will 
equal the area of the main A. What must the size of C be ? 

The size of C is found by simply taking a rule 20 inches 
long and placing one end on the arm of the square in Fig. 11, on 
the number 12, when the opposite end of the rule will touch the 
number 16. Then 16 is the required size of the branch C in Fig. 
12. We can prove this by computation which, however, is not 
necessary in practice. The area of a 20- inch round pipe equals 
314.16 in.; area of 12-in. pipe = 113.098 in.; area of 16-in. 
pipe = 201.062 in.; and 113.098 in. + 201.062 in. = 314.160 in. 
The area of a 20-in. square pipe = 400 in.; area of 12-in. square 
pipe = 144 in.; area of 16-in. square pipe = 256 in.; and 
256 in. + 144 in. = 400 in. 



PROBLEMS IN MENSURATION 



Suppose any two branches are given as B and C in Fig. 12, 
what must the size of A be so that its area will have the com- 
bined area of the two branches ? 

Simply set the rule on the numbers 12 and 16 on the two 
-^ ( arms of the square respectively, and the length 
^y from a to b in Fig. 11 will measure 20 inches. 
If A, Fig. 12, were given, and two branches 
were required, so that B and C were both of 
equal size, then simply set the rule 20 inches 
long, on both arms of the square so that the 
distance from O to c and O to d would be 
equal, as shown in Fig. 11, which would be 
found to measure 14^ in. plus a least trifle. 
This rule can be used to advantage for any size round or square 
pipe in blower, blast, heat, and ventilating piping, saving time and 
trouble in computation. Where no square is at hand, one can be 
drawn on paper and used for work of this kind. 




/ • 



INDEX 



A Page 

Approximate developments 22 

Architectural sheet-metal work 193 

Architrave 194 

B 

Bars for skylights 136 

Bath tub 32 

Bead-mould 203 

Bed-mould 194 

C 

Cavetto moulding 203 

Conical boss 27 

Construction of articles from sheet metal 3 

Coppersmith's problems ' 105 

brewing kettle 115 

circular tank 107 

curved elbow 113 

sphere 105 

Cornice work 193 

construction 193 

mouldings, shapes of 202 

patterns 200 

tools 200 

Corrugated iron roofing 158 

Corrugated iron roofing and siding 182 

laying 185 

tables 184 

Corrugated siding, laying 190 

Crown-mould 194 

Curved mouldings, development of blanks for 249-262 

Cyma recta moulding 202 

Cyma reversa moulding 203 

D 

Dentil course 194 

Developments, approximate 22 

Developments by triangulation 15 

Dividers 163 

Double-pitch skylight ,...,' 142 

Drips 194 



264 INDEX 

E Page 

Echinus moulding 203 

Elbows 44 

five-pieced 46 

four- pieced 46 

tapering two-pieced 50 

three-pieced 45 

Elevation, definition of 196 

Emerson ventilator 41 

Entablature 194 

F 

Flashing chimney 187 

Flat extension skylight 142 

Flat-seam roofing 167 

table 159 

Foot-moulding 194 

Frieze 194 

Funnel strainer pail 36 

H 

Hammers 163 

Heavy metal problems 116 

boiler stack 117 

conical piece connecting two boilers 128 

gusset sheet on locomotive 126 

scroll sign 128 

three-pieced elbow 122 

Hip bath 30 

Hipped skylight 143 

development of patterns for 144 

I 

Intersections and developments 5 

cylinder and octagonal prism 5 

hexagonal and quadrangular prism 7 

quadrangular prism and sphere 13 

two cylinders of equal diameters at right angles 9 

two cylinders of unequal diameters at angle of 45° 11 

J 

Jack bar 150 

L 

Light gauge metal problems 75 

curved rectangular chute 82 

cylinder intersecting conical surface • ■ 100 

hopper register box 85 

oblique piping 75 

offset 88 

rain-water cut-off 77 



INDEX 265 

Light gauge metal problems Page 

tapering flange 97 

three-way branch 90 

two-branch fork 94 

M 

Mallet 163 

Metal roofing 158 

tables „ 159-161 

tools 163 

Metal slates and shingles 162 

Micrometer caliper 4 

Miter, definition of : . . . 196 

Miter cutting 204 

angular pediment with horizontal returns 219 

eye-brow dormer 243 

gable moulding intersecting a pilaster 216 

gable moulding mitering on a wash 217 

gable moulding in octagon plan 224 

gore piece joined to a chamfer 235 

gutter or eavetrough 233 

hip ridge 237 

horizontal moulding butting against pitched roof 207 

moulding which miters at an angle other than right 212 

panel or face miter 209 

raking bracket in gable moulding 230 

segmental pediment with upper and lower horizontal returns 223 

six-pointed star . 236 

spire, square in plan, intersecting four gables 228 

square return miter 205 

turret with four gables 219 

two mouldings having different profiles to miter together 213 

Modillion course 194 

Mouldings 202 

cavetto 203 

cyma recta 202 

cyma reversa 203 

echinus 203 

torus 203 

N 

Notching machine 163 

O 

Oblique piping 75 

P 

Panels 194 

Pitched skylights 134 

Planceer 194 



266 INDEX 

Page 

Problems, coppersmith's 105 

Problems in heavy metal work 116 

Problems in light gauge metal 75 

Problems in sheet-metal work 26 

bath tub 32 

elbows 44 

Emerson ventilator 41 

faucet, joining of to sheet-metal tank 27 

funnel strainer pail 36 

hip bath 30 

sink drainer 26 

R 

Rain-water cut-off 77 

Raising sash 139 

Raking mouldings 196 

Roman mouldings 202 

Roof mensuration 163 

Roofing 158 

corrugated iron 182 

flat-seam 167 

table 159 

standing-seam 177 

table 160 

tin plate data 161 

tools 163 

Roofing folders 163 

Roofing tin 158 

S 

Scraper 163 

Shears 163 

Sheet-metal cornices 193 

Sheet metal work 

coppersmith's problems 105 

cornices 193 

heavy metal problems 116 

light gauge metal problems 75 

miter cutting 204 

plates 75-79, 133-135 

roofing 158 

skylights ^ 133 

Shop tools 4 

Single-pitch skylight 141 

Sink drainer 26 

Skylights 133 

bars, various shapes of 136 

construction 133 

curbs, various shapes of 137 



INDEX 26? 

Skylights Page 

double-pitch 142 

flat extension 142 

hipped 143 

raising sash . .- 139 

shop tools * 136 

single-pitch 141 

Soldering 172 

Soldering copper 163 

Standing-seam roofing 177 

table 160 

Stretch-awl ., 163 

T 
Tables 

angle iron, weight of 74 

cast iron, wrought iron, copper, lead, brass, and zinc, weight of . . . . 62 

corrugated sheets, measurements of 184 

flat rolled iron, weights of 66-71 

flat-seam roofing 159 

iron bars, square and round 72, 73 

rough glass, weight of, per sq. ft 135 

sheet copper '63 

sheet iron and steel, standard gauge for 65 

sheet zinc 64 

standing-seam roofing 160 

tee iron, weight of 74 

tin plates, net weight per box 161 

tin plates, standard weights and gauges of <- 161 

Terne plate 158 

Tools required by metal roofers 163 

-ools used in cornice work 200 

Torus moulding 203 

Triangulation, developments by 15 

Turret sash 152 

W 

Workshop problems 26 





LIBRARY OF CONGRESS 

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